Pyrrolidine derivatives

ABSTRACT

The present invention relates to pyrrolidine derivatives useful as inhibitors of metalloproteases, e.g. zinc proteases, and which are effective in treating disease states associated with vasoconstriction.

[0001] This application is a divisional of Ser. No. 09/906,980, filedJul. 17, 2001, currently pending.

BACKGROUND OF THE INVENTION

[0002] Endothelins are peptides that exist in three isoforms, ET-1,ET-2, and ET-3, each encoded by a distinct gene. They have beenoriginally discovered in the conditioned medium of porcine endothelialcells in 1988 by Yanagisawa (Yanagisawa M; Kurihara H; Kimura S; TomobeY; Kobayashi M; Mitsui Y; Yazaki Y; Goto K; Masaki T: A novel potentvasoconstrictor peptide produced by vascular endothelial cells [seecomments]. NATURE (Mar. 31, 1988), 332(6163), 411-5.). The active ETsare peptides of 21 amino acids with two intramolecular disulfidebridges. They are produced from preproproteins of 203 to 212 aminoacids, which are processed by furin-like endopeptidases to thebiologically inactive big-endothelin (big-ET). The big-ETs arespecifically processed to mature ETs by a hydrolytic cleavage betweenamino acids 21 and 22 that are Trp²¹-Val²² (big-ET-1, big ET-2) andTrp²¹-Ile²² in big-ET-3 respectively. Already in 1988 a specificmetalloprotease was postulated to be responsible for this specificcleavage. In 1994 ECE-1 (endothelin converting enzyme-1) was purifiedand cloned from bovine adrenal (Xu D, Emoto N, Giaid A, Slaughter C, KawS, de Witt D, Yanagisawa M: ECE-1: a membrane-bound metalloprotease thatcatalyzes the proteolytic activation of big endothelin-1. Cell (1994)78: 473-485).

[0003] ECE-1 is a membrane bound type II zinc-endopeptidase with aneutral pH optimum and a zinc binding motif HExxHx(>20)E. It belongs tosubfamily M13 and has a large 681 amino acid ectodomain that comprisesthe active site. Other members of the M13 family are NEP24.11 (neutralendopeptidase), PEX, a phosphate regulating neutral endopeptidase, andKell blood group protein that has recently been described as a big-ET-3processing enzyme. Members of the M13 family of human origin arecharacterized by a high molecular weight (>80 kDa) a number of conserveddisulfide bridges and a complex glycosylation pattern. The structure ofNEP has recently been solved. (Oefner et al, J. Mol. Biol. 2000, 296,341-349). The catalytic domain of ECE and related human M13 proteinasesare significantly larger (>650 amino acids) than members of matrixmetalloproteases (MMPs). Unlike the family of the MMPs which belong tothe metzincins and display a typical HExxHxxGxxH pattern members of theM13 family are gluzincins comprising a HExxHx(>20)E pattern. These twofamilies are clearly different in size of catalytic domains, structureand zinc coordinating pattern of ligands. Active sites of the twofamilies show clear differences which has clear impact on type ofinhibitors and the potential selectivity.

SUMMARY OF THE INVENTION

[0004] The present invention relates to compounds of formula (I)

[0005] wherein

[0006] R¹ is hydrogen, alkylcarbonyl, or arylcarbonyl;

[0007] R² is alkyl, alkenyl, alkinyl, cyanoalkyl, hydroxyalkyl,carboxyalkyl, alkoxycarbonyl, alkylcarbonylalkyl, alkylcycloalkyl,alkylcycloalkylalkyl, alkylsulfonyl, aryl, arylalkyl, arylalkoxyalkyl,aryl(alkoxycarbonyl)alkyl, arylcarbamoyl, diarylalkyl,aryl(carboxyalkyl)amide, arylamino, arylcarbonyl, arylsulfonyl,cycloalkyl, cycloalkylcarbonyl, cycloalkylalkyl, heteroaryl,heteroarylalkyl, heterocyclylalkyl, or the group YR² is heterocyclyl orR² is a group of the formula

[0008] R³ is alkyl, alkylcycloalkyl, alkylcycloalkylalkyl, cycloalkyl,halogenalkyl, carboxyalkyl, aminoalkyl, dialkylaminoalkyl, alkoxyalkyl,alkoxycarbonylalkyl, alkinyl, aryl, arylalkyl,arylalkyl(alkoxycarbonyl)alkyl, arylcarbonylalkyl, aryloxyalkyl,arylalkenyl, aryl(alkoxycarbonyl)alkyl, heteroaryl, heteroarylalkyl,heterocyclyl or heterocycylalkyl, and R³ is hydroxy in case of X is SO₂;

[0009] R⁴ is hydrogen in case m=1 or alkyl or hydrogen in case m=0;

[0010] R⁵ is hydrogen, alkyl, aryl, or carboxyalkyl;

[0011] R⁶ is hydrogen, alkyl, aryl, carboxyalkyl, arylcarbonyl,alkylcarbonyl, arylalkoxycarbonyl, or arylalkyl;

[0012] R⁷ is hydrogen, aryl, alkyl, arylalkyl, heterocyclylalkyl,arylamino, alkyl(arylalkyl)amino, alkoxycarbonylalkyl, carboxyalkyl, oralkylthioalkyl;

[0013] R⁸ is hydroxy, alkyl, aryl, cyanoalkyl, alkoxy, arylalkyl,arylalkoxy, mono- or dialkylamino, arylamino, aryl(alkyl)amino,cyanoalkylamino, arylalkyl(alkyl)amino, heteroaryl, heteroarylalkyl, orheterocyclyl; and

[0014] X is —S(O)₂—, —S(O)₂—NH—, —C(O)—, —C(O)NR⁵—, C(O)O—;

[0015] Y is —CH₂, —O—, —NR⁶— or —S—;

[0016] m and p independently are 0 or 1, n and q independently are 1, 2or 3 and o is 0, 1 or 2 with the proviso that the sum of n, o and p is≧2 and ≦3; and

[0017] dimeric forms, and/or pharmaceutically acceptable esters, and/orpharmaceutically acceptable salts thereof, preferably pharmaceuticallyacceptable esters, and/or pharmaceutically acceptable salts thereof, andmost preferably pharmaceutically acceptable salts thereof.

[0018] The present invention is directed to compounds which are usefulas inhibitors of metalloproteases, e.g. zinc proteases, particularlyzinc hydrolases, and which are effective in the prophylaxis andtreatment of disease states which are associated with vasoconstrictionof increasing occurrences. Examples of such disorders are high bloodpressure, coronary disorders, cardiac insufficiency, renal andmyocardial ischaemia, renal insufficiency, dialysis, cerebral ischaemia,cardiac infarct, migraine, subarachnoid haemorrhage, Raynaud syndromeand pulmonary high pressure. In addition the compounds are useful ascytostatic and cerebroprotective agents for inhibition of graftrejection, for organ protection and for treatment of ophthalmologicaldiseases.

DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention is directed to compounds of formula (I):

[0020] wherein

[0021] R¹ is hydrogen, alkylcarbonyl, or arylcarbonyl;

[0022] R² is alkyl, alkenyl, alkinyl, cyanoalkyl, hydroxyalkyl,carboxyalkyl, alkoxycarbonyl, alkylcarbonylalkyl, alkylcycloalkyl,alkylcycloalkylalkyl, alkylsulfonyl, aryl, arylalkyl, arylalkoxyalkyl,aryl(alkoxycarbonyl)alkyl, arylcarbamoyl, diarylalkyl,aryl(carboxyalkyl)amide, arylamino, arylcarbonyl, arylsulfonyl,cycloalkyl, cycloalkylcarbonyl, cycloalkylalkyl, heteroaryl,heteroarylalkyl, heterocyclylalkyl, or the group YR² is heterocyclyl orR² is a group of the formula

[0023] R³ is alkyl, alkylcycloalkyl, alkylcycloalkylalkyl, cycloalkyl,halogenalkyl, carboxyalkyl, aminoalkyl, dialkylaminoalkyl, alkoxyalkyl,alkoxycarbonylalkyl, alkinyl, aryl, arylalkyl,arylalkyl(alkoxycarbonyl)alkyl, arylcarbonylalkyl, aryloxyalkyl,arylalkenyl, aryl(alkoxycarbonyl)alkyl, heteroaryl, heteroarylalkyl,heterocyclyl or heterocycylalkyl, and R³ is hydroxy in case of X is SO₂;

[0024] R⁴ is hydrogen in case m=1 or alkyl or hydrogen in case m 0;

[0025] R⁵ is hydrogen, alkyl, aryl, or carboxyalkyl;

[0026] R⁶ is hydrogen, alkyl, aryl, carboxyalkyl, arylcarbonyl,alkylcarbonyl, arylalkoxycarbonyl, or arylalkyl;

[0027] R⁷ is hydrogen, aryl, alkyl, arylalkyl, heterocyclylalkyl,arylamino, alkyl(arylalkyl)amino, alkoxycarbonylalkyl, carboxyalkyl, oralkylthioalkyl;

[0028] R⁸ is hydroxy, alkyl, aryl, cyanoalkyl, alkoxy, arylalkyl,arylalkoxy, mono- or dialkylamino, arylamino, aryl(alkyl)amino,cyanoalkylamino, arylalkyl(alkyl)amino, heteroaryl, heteroarylalkyl, orheterocyclyl;

[0029] X is —S(O)₂—, —S(O)₂—NH—, —C(O)—, —C(O)NR⁵—, C(O)O—;

[0030] Y is —CH₂, —O—, —NR₆— or —S—;

[0031] m and p independently are 0 or 1, n and q independently are 1, 2or 3 and o is 0, 1 or 2 with the proviso that the sum of n, o and p is≧2 and ≦3; and

[0032] dimeric forms, and/or pharmaceutically acceptable esters, and/orpharmaceutically acceptable salts thereof.

[0033] The term “alkyl”, alone or in combination, means a straight-chainor branched-chain alkyl group containing a maximum of 7, preferably amaximum of 4, carbon atoms, e.g., methyl, ethyl, n-propyl,2-methylpropyl (iso-butyl), 1-methylethyl (iso-propyl), n-butyl, and1,1-dimethylethyl (t-butyl).

[0034] The term “carboxy” refers to the group —C(O)OH.

[0035] The term “carbamoyl” refers to the group —C(O)NH₂.

[0036] The term “carbonyl” refers to the group —C(O)—.

[0037] The term “halogen” refers to the group fluoro, bromo, chloro andiodo.

[0038] The term “sulfonyl” refers to the group —S(O₂)—.

[0039] The term “alkenyl” refers to a hydrocarbon chain as defined foralkyl having at least one olefinic double bond (including for example,vinyl, allyl and butenyl).

[0040] The term “alkinyl” refers to a hydrocarbon chain as defined foralkyl having at least one olefinic triple bond (including for examplepropinyl, butin-(1)-yl, etc.

[0041] The term “alkoxy”, alone or in combination, means an alkyl ethergroup in which the term ‘alkyl’ has the significance given earlier, suchas methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy,sec.butoxy, tert.butoxy and the like.

[0042] The term “alkoxycarbonyl” refers to a group of the formula—C(O)R_(c) wherein R_(c) is alkoxy as defined above.

[0043] The term “hydroxy” refers to the group —OH, the term “cyano” tothe group —CN.

[0044] The term “hydroxyalkyl” means an alkyl group as defined abovewhich is substituted by a hydroxy group.

[0045] The term “thioalkyl” and “cyanoalkyl” refer to an alkyl group asdefined above which is substituted by a —SH group or an —CN group,respectively.

[0046] The term “halogenalkyl” refers to an alkyl group as defined abovewhich is substituted by one to three halogen atoms, preferably fluoro,e.g. trifluoromethyl, 2,2,2-trifluoroethyl, etc.

[0047] The term “alkylthioalkyl” is a group of the formulaalkyl-S-alkyl.

[0048] “Carboxyalkyl” means an alkyl as defined above which issubstituted by a HOOC-group.

[0049] The term “alkylcarbonyl”, alone or in combination, means an acylgroup derived from an alkanecarboxylic acid, i.e. alkyl-C(O)—, such asacetyl, propionyl, butyryl, valeryl, 4-methylvaleryl etc.

[0050] The term “cycloalkyl” signifies a saturated, cyclic hydrocarbongroup with 3-8, preferably 3-6 carbon atoms, i.e. cyclopropyl,cyclobutyl, cyclopentyl and cyclohexyl and the like.

[0051] The term “amino” refers to the group —NH₂.

[0052] The term “aryl” for R²—alone or in combination—, refers to anaromatic carbocyclic radical, i.e. a 6 or 10 membered aromatic orpartially aromatic ring, e.g. phenyl, naphthyl or tetrahydronaphthyl,preferably phenyl or naphthyl, and most preferably phenyl. The arylmoiety is optionally substituted with one or more groups independentlyselected from halogen, preferably fluoro, alkoxycarbonyl, e.g.methylcarbonyl, carboxy, cyano, alkyl, alkoxy, phenyl, phenoxy,trifluormethyl, trifluormethoxy, 1,3-dioxolyl, or 1,4-dioxolyl, morepreferably fluor, alkoxycarbonyl, alkyl, trifluoromethyl andtrifluoromethoxy and most preferably fluor. The most preferred aromaticgroups are 2,5-difluorobenzyl and 2,4,5-trifluorobenzyl.

[0053] The term “aryl” for R³—alone or in combination—, refers to anaromatic carbocyclic radical, i.e. a 6 or 10 membered aromatic orpartially aromatic ring, e.g. phenyl, naphthyl or tetrahydronaphthyl,preferably phenyl or naphthyl, and most preferably phenyl. The arylmoiety is optionally substituted with one or more groups independentlyselected from halogen, alkoxycarbonyl, e.g. methylcarbonyl, carboxy,cyano, alkyl, alkoxy, phenyl, phenoxy, trifluormethyl, trifluormethoxy,1,3-dioxolyl, or 1,4-dioxolyl, cyclohexyl, hydroxy, alkylamido, e.g.acetamido, nitro, alkylsulfonyl, e.g. methylsulfonyl, more preferablyfluoro, chloro, bromo, alkoxy, carboxy, 1,4-dioxolyl, alkoxycarbonyl.The most preferred aromatic groups are phenyl, 4-fluorobenzyl,4-carboxybenzyl, 2,3-dihydrobenzo[1,4]dioxihyl, 2-bromophenyl,2-fluorophenyl, 2-methoxycarbonylphenyl, naphthyl and 4-methoxyphenyl.

[0054] The term “aryl” for R⁴ to R¹⁰—alone or in combination—refers toan aromatic carbocyclic radical, i.e. a 6 or 10 membered aromatic orpartially aromatic ring, e.g. phenyl, naphthyl or tetrahydronaphthyl,preferably phenyl or naphthyl, and most preferably phenyl. The arylmoiety is optionally substituted with one or more groups independentlyselected from halogen, preferably fluor, alkoxycarbonyl, e.g.methylcarbonyl, carboxy, cyano, alkyl, alkoxy, phenyl, phenoxy,trifluormethyl, trifluormethoxy, hydroxy, alkylamido, e.g. acetamido,nitro, alkylsulfonyl, e.g. methylsulfonyl, more preferably alkyl oralkoxy.

[0055] The term “aryloxy” refers to an aryl group as defined aboveattached to a parent structure via an oxy radical, i.e., aryl-O—.

[0056] The term “heteroaryl” for R² and R⁴ to R¹⁰—alone or incombination—refers to an aromatic mono- or bicyclic radical having 5 to10, preferably 5 to 6 ring atoms, containing one to three heteroatoms,preferably one heteroatom, e.g. independently selected from nitrogen,oxygen or sulfur. Examples of heteroaryl groups are thiophenyl,isoxazolyl, thiazolyl, pyridinyl, pyrrolyl, imidazolyl, tetrazolyl,preferably pyridinyl, isoxazolyl or thiazolyl. Optionally, theheteroaryl group can be mono-, di- or tri-substituted, independently,with phenyl, alkyl, alkylcarbonyl, alkoxycarbonyl, hydroxy, amino,alkylamino, dialkylamino, carboxy, alkoxycarbonylalkyl, preferablyalkyl.

[0057] The term “heteroaryl” for R³—alone or in combination—refers to anaromatic mono- or bicyclic radical having 5 to 10, preferably 5 to 6ring atoms, containing one to three heteroatoms, preferably oneheteroatom, e.g. independently selected from nitrogen, oxygen or sulfur.Examples of heteroaryl groups are pyridinyl, thiophenyl, isoxyzolyl,isoquinolyl, quinolyl, and 1H-benzo[d][1,3]oxazin-2,4-dione and indolyl,pyrimidine, pyridazine, and pyrazine, preferably pyridinyl, thiophenyl,isoxazolyl, isoquinolyl, quinolyl, and 1H-benzo[d][1,3]oxazin-2,4-dioneand indolyl. Optionally, the heteroaryl group can be mono-, di- ortri-substituted, independently, with phenyl, alkyl, alkylcarbonyl,alkoxycarbonyl, hydroxy, amino, alkylamino, dialkylamino, carboxy, oxo,alkoxycarbonylalkyl, preferably alkyl.

[0058] The term “heterocyclyl”—alone or in combination—refers to anon-aromatic mono- or bicyclic radical having 5 to 10, preferably 5 to 6ring atoms, containing one to three heteroatoms, preferably oneheteroatom, e.g. independently selected from nitrogen, oxygen or sulfur.Optionally the heterocyclic ring can be substituted by a groupindependently selected from halogen, alkyl, alkoxy, oxocarboxy,alkoxycarbonyl, etc. and/or on a secondary nitrogen atom (i.e. —NH⁻) byalkyl, arylalkoxycarbonyl, alkylcarbonyl or on a tertiary nitrogen atom(i.e. ═N—) by oxido. Examples for heterocyclic groups are morpholinyl,pyrrolidinyl, piperidyl, etc., and especially for R²alkyl-pyran-triol-yl.

[0059] The term “dimeric form” means a compound wherein the two R¹groups of two identical compounds of formula I have been replaced by acommon single bond or wherein R¹ is glutathione-S— or cysteine-S— orester and/or alkylcarbonyl or arylcarbonyl derivatives thereof, e.g.acetylcysteine-S— or benzoylcysteine-S—, preferably glutathione-S—,cysteine-S—, acetylcysteine-S— or benzoylcysteine-S—.

[0060] The term “pharmaceutically acceptable salt” refers to those saltsthat retain the biological effectiveness and properties of the freebases or free acids, which are not biologically or otherwiseundesirable. The salts are formed with inorganic acids such ashydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid,phosphoric acid and the like, and organic acids such as acetic acid,propionic acid, glycolic acid, pyruvic acid, oxylic acid, maleic acid,malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid,benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid,ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid,N-acetylcystein and the like. In addition these salts may be preparedfrom addition of an inorganic base or an organic base to the free acid.Salts derived from an inorganic base include, but are not limited to,the sodium, potassium, lithium, ammonium, calcium, magnesium salts andthe like. Salts derived from organic bases include, but are not limitedto salts of primary, secondary, and tertiary amines, substituted aminesincluding naturally occurring substituted amines, cyclic amines andbasic ion exchange resins, such as isopropylamine, trimethylamine,diethylamine, triethylamine, tripropylamine, ethanolamine, lysine,arginine, N-ethylpiperidine, piperidine, polymine resins and the like.

[0061] “Pharmaceutically acceptable esters” means that compounds ofgeneral formula (I) may be derivatised at functional groups to providederivatives which are capable of conversion back to the parent compoundsin vivo. Examples of such compounds include physiologically acceptableand metabolically labile ester derivatives, such as methoxymethylesters, methylthiomethyl esters and pivaloyloxymethyl esters.Additionally, any physiologically acceptable equivalents of thecompounds of general formula (I), similar to the metabolically labileesters, which are capable of producing the parent compounds of generalformula (I) in vivo, are within the scope of this invention.

[0062] The compounds of formula (I) are useful in inhibiting mammalianmetalloprotease activity, particularly zinc hydrolase activity. Morespecifically, the compounds of formula (I) are useful as medicaments forthe treatment and prophylaxis of disorders which are associated withdiseases caused by endothelin-converting enzyme (ECE) activity.Inhibiting of this enzyme would be useful for treating myocardialischaemia, congestive heart failure, arrhythmia, hypertension, pulmonaryhypertension, asthma, cerebral vasospasm, subarachnoid haemorrhage,pre-eclampsia, kidney diseases, atherosclerosis, Buerger's disease,Takayasu's arthritis, diabetic complications, lung cancer, prostaticcancer, gastrointestinal disorders, endotoxic shock and septicaemia, andfor wound healing and control of menstruation, glaucoma. In addition thecompounds are useful as cytostatic and cerebroprotective agents forinhibition of graft rejection, for organ protection and for treatment ofophthalmological diseases.

[0063] In a preferred embodiment, the present invention comprisescompounds of formula (I) wherein m and p are 0, n, o and q are 1. Morespecifically, the present invention comprises the above definedcompounds of general formula (III).

[0064] wherein R¹, R², R³, R⁴, X and Y are as defined as above.

[0065] In a preferred embodiment of the present invention, R¹ ishydrogen or alkylcarbonyl, preferably hydrogen or acetyl, and morepreferably hydrogen.

[0066] In a further preferred embodiment of the present R² is aryl,arylalkyl, arylalkoxyalkyl, arylcarbamoyl, arylamino, arylcarbonyl,arylsulfonyl, cycloalkyl, cycloalkylcarbonyl, cycloalkylalkyl orheteroarylalkyl, more preferably aryl, arylalkyl, arylcarbamoyl,arylamino, arylcarbonyl, arylsulfonyl or heteroarylalkyl. In the mostpreferred R² is arylalkyl and specifically phenylalkyl optionallysubstituted with 2 to 3 halogen atoms, e.g. 2,4,5-trifluoro-benzyl or2,5-difluoro-benzyl.

[0067] According to the present invention R³ is preferably alkyl,halogenalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, cycloalkyl,halogenalkyl, alkoxyalkyl, alkoxycarbonylalkyl, alkinyl, aryl,arylalkyl, arylalkyl(alkoxycarbonyl)alkyl, arylcarbonylalkyl,aryloxyalkyl, arylalkenyl, aryl(alkoxycarbonyl)alkyl, heteroaryl,heteroarylalkyl or heterocyclyl, more preferably alkyl, arylalkyl,arylcarbonylalkyl, aryloxylakyl, alkylcycloalkyl, alkylcycloylkylalkyl,cycloalkyl, heteroarylalkyl or halogenalkyl and most preferably alkyl,arylalkyl, aryl, aryloxyalkyl or halogenalkyl, e.g. phenoxy-ethyl,2,2,2-trifluoro-ethyl, 4-fluoro-benzyl, 4-carboxy-benzyl,2,3-dihydrobenzo[1,4]dioxin-5-yl, 2-bromophenyl, butane-1-yl, methyl,benzyl, tert-butyl, 2-fluoro-phenyl, 4-fluoro-phenyl,2-methoxy-carbonylphenyl, isopropyl, naphthalen-2-yl, naphthalen-2-yl,or 4-methoxy-phenyl.

[0068] In a preferred embodiment R⁴ is hydrogen.

[0069] In the above-defined compounds X is preferably —S(O)₂—,—S(O)₂—NH—, —C(O)NR⁵— or C(O)O—, and more preferably —S(O)₂—, —C(O)NH—or C(O)O—.

[0070] The invention comprises compounds as defined above, wherein R⁵ ishydrogen, alkyl or carboxyalkyl, preferably hydrogen.

[0071] R⁶ in the compounds described above is preferably hydrogen, alkylor arylalkyl and more preferably hydrogen.

[0072] In further preferred embodiments of the present invention R⁷ ishydrogen or aryl and R⁸ is hydroxy or alkoxy.

[0073] In the present invention Y preferably is —O— or —NH—.

[0074] More specifically the invention comprises the above compoundswherein R¹ is hydrogen or alkylcarbonyl, R² is phenylalkyl substitutedwith 2 to 3 halogen; R³ is alkyl, aryl, arylalkyl, aryloxyalkyl orhalogenalkyl, e.g. e.g. phenoxy-ethyl, 2,2,2-trifluoro-ethyl,4-fluoro-benzyl, 4-carboxy-benzyl, 2,3-dihydrobenzo[1,4]dioxin-5-yl,2-bromophenyl, butane-1-yl, methyl, benzyl, tert-butyl, 2-fluoro-phenyl,4-fluoro-phenyl, 2-methoxy-carbonylphenyl, isopropyl, naphthalen-2-yl,naphthalen-2-yl, or 4-methoxy-phenyl;

[0075] X is —SO₂—, —CONH—, —C(O)—O—; and Y is —NH— or —O—.

[0076] The present invention comprises compounds as defined above withthe stereochemistry shown in formula (IV)

[0077] wherein R¹, R², R³, R⁴, X and Y are as defined above.

[0078] In the most preferred embodiment the invention comprisescompounds of formula (IV) wherein R¹ is hydrogen or acetyl and R² isdifluorobenzyl or trifluorobenzyl, e.g. 2,4,5-trifluoro-benzyl or2,5-difluoro-benzyl- and R³ is phenoxy-ethyl, 2,2,2-trifluoro-ethyl,4-fluoro-benzyl, 4-carboxy-benzyl, 2,3-dihydrobenzo[1,4]dioxin-5-yl,2-bromophenyl, butane-1-yl, methyl, benzyl, tert-butyl, 2-fluoro-phenyl,4-fluoro-phenyl, 2-methoxy-carbonylphenyl, isopropyl, naphthalen-2-yl,naphthalen-2-yl, or 4-methoxy-phenyl and R⁴ is hydrogen, X is —S(O)₂—,—C(O)NH— or C(O)O— and Y is —O— or —NH—.

[0079] Preferred embodiments of the present invention are the compoundsexemplified in the examples. Especially, the invention comprises thefollowing compounds selected from the group consisting of

[0080] a)(3R,5S)-5-[(2,5-Difluoro-benzylamino)-methyl]-1-(naphthalene-2-sulfonyl)pyrrolidine-3-thiol;

[0081] b)(2S,4R)-2-[(2,5-Difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid (2-fluoro-phenyl)-amide;

[0082] c)(2S,4R)-2-[(2,5-Difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid 4-methoxy-phenyl ester;

[0083] d)(2S,4R)-2-[(2,5-Difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid 4-fluoro-phenyl ester;

[0084] e)2S,4R)-2-[(2,5-Difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid isopropyl ester;

[0085] f)(2S,4R)-2-[(2,5-Difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid naphthalen-2-yl ester;

[0086] g)(2S,4R)-2-[(2,5-Difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo [1,4]dioxin-5-yl ester;

[0087] h)(2S,4R)-2-[(2,5-Difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid butyl ester;

[0088] i)(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid isopropyl ester;

[0089] j)(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo[1,4]dioxin-5-yl ester;

[0090] k)(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester;

[0091] l)(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid butyl ester;

[0092] m)(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2-fluoro-phenyl ester;

[0093] n)(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2-methoxycarbonyl-phenyl ester;

[0094] o)(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2-bromo-phenyl ester;

[0095] p)(3R,5S)-1-(Butane-1-sulfonyl)-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-3-thiol;

[0096] q)(3R,5S)-1-Methanesulfonyl-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-3-thiol;

[0097] r)(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid benzylamide;

[0098] s)4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid butylamide;

[0099] t)4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid (2-phenoxy-ethyl)-amide;

[0100] u)4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid (2,2,2-trifluoro-ethyl)-amide;

[0101] v)4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid 4-fluoro-benzylamide;

[0102] w)4-{[4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonylamino]-methyl}-benzoicacid;

[0103] x)(2S,4R)-4-Acetylsulfanyl-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo [1,4]dioxin-5-yl ester;

[0104] y)(2S,4R)-4-Acetylsulfanyl-2-[(2,5-difluoro-benzylamino)-methyl]-pyrrolidine-1-carboxylicacid butyl ester; and

[0105] z)(2S,4R)-4-Acetylsulfanyl-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2-methoxycarbonyl-phenyl ester.

[0106] These compounds show activity values of 0.5 nM to 100 nM in theradioimmunoassay (E and F), see below.

[0107] The invention also refers to pharmaceutical compositionscontaining a compound as defined above and a pharmaceutically acceptableexcipient.

[0108] A further embodiment of the present invention refers to the useof compounds as defined above as active ingredients in the manufactureof medicaments comprising a compound as defined above for theprophylaxis and treatment of disorders which are caused byendothelin-converting enzyme (ECE) activity especially myocardialischaemia, congestive heart failure, arrhythmia, hypertension, pulmonaryhypertension, asthma, cerebral vasospasm, subarachnoid haemorrhage,pre-eclampsia, kidney diseases, atherosclerosis, Buerger's disease,Takayasu's arthritis, diabetic complications, lung cancer, prostaticcancer, gastrointestinal disorders, endotoxic shock and septicaemia, andfor wound healing and control of menstruation, glaucoma, graftrejection, diseases associated with cytostatic, ophthalmological, andcerebroprotective indications, and organ protection.

[0109] Further the invention refers to the use of compounds as describedabove for the treatment or prophylaxis of diseases which are associatedwith myocardial ischaemia, congestive head failure, arrhythmia,hypertension, pulmonary hypertension, asthma, cerebral vasospasm,subarachnoid haemorrhage, pre-eclampsia, kidney diseases,atherosclerosis, Buerger's disease, Takayasu's arthritis, diabeticcomplications, lung cancer, prostatic cancer, gastrointestinaldisorders, endotoxic shock and septicaemia, and for wound healing andcontrol of menstruation, glaucoma, graft rejection, diseases associatedwith cytostatic, ophthalmological, and cerebroprotective indications,and organ protection.

[0110] In addition the invention comprises compounds as described abovefor use as therapeutic active substances, in particular in context withdiseases which are associated with zinc hydrolase activity such asmyocardial ischaemia, congestive heart failure, arrhythmia,hypertension, pulmonary hypertension, asthma, cerebral vasospasm,subarachnoid haemorrhage, pre-eclampsia, kidney diseases,atherosclerosis, Buerger's disease, Takayasu's arthritis, diabeticcomplications, lung cancer, prostatic cancer, gastrointestinaldisorders, endotoxic shock and septicaemia, and for wound healing andcontrol of menstruation, glaucoma, graft rejection, diseases associatedwith cytostatic, ophthalmological, and cerebroprotective indications,and organ protection.

[0111] The invention also comprises a method for the therapeutic and/orprophylactic treatment of myocardial ischaemia, congestive heartfailure, arrhythmia, hypertension, pulmonary hypertension, asthma,cerebral vasospasm, subarachnoid haemorrhage, pre-eclampsia, kidneydiseases, atherosclerosis, Buerger's disease, Takayasu's arthritis,diabetic complications, lung cancer, prostatic cancer, gastrointestinaldisorders, endotoxic shock and septicaemia, and for wound healing andcontrol of menstruation, glaucoma, graft rejection, diseases associatedwith cytostatic, ophthalmological, and cerebroprotective indications,and organ protection, which method comprises administering a compound asdefined above to a human being or animal.

[0112] The invention also relates to the use of compounds as definedabove for the inhibition of zinc hydrolase activity.

[0113] The invention also refers to the above compounds whenevermanufactured by a process as described below.

[0114] Compounds of formula (I) can be prepared by methods known in theart or as described below. Unless otherwise indicated, the substituentsR¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, X, Y, m, p, n, q are as described above.

[0115] Step a) of scheme I describes the persilylation of hydroxy- andamino groups, e.g. by reaction of compound 1 withhexamethyldisilazan/140° C. followed by reaction with R³SO₂Cl in THF ordi-t-butyldicarbonate/NaHCO₃ in dioxane/H₂O (BOC protection). Forinversion of the configuration (via mesylate) the resulting alcohol 2 istreated with MeSO₃H/Ph₃P/DIAD in toluene (room temperature to 80° C.) or(via bromide) with LiBr/DEAD/Ph₃P in THF (4° C. to room temperature) or(via chloride) with Ph₃P/CCl₄ in CH₂Cl₂ (3° C. to room temperature). Incase of retention of the configuration (via mesylate) alcohol 2 can betransformed to a compound of formula 3 by reaction withMeSO₂Cl/pyridine/DMAP (0° C. to room temperature).

[0116] For the introduction of a protected thio moiety, e.g.triphenylmethanethiol or 4-methoxy-benzylmercaptane, compound of formula3 are treated with K-Ot-Bu in DMF (for Br: 0° C. to room temperature;for Cl: 0° C.; for Mes: room temperature to 100° C. For step d thecorresponding compounds of formula 4, 8 and 9 can be obtained accordingto methods known in the art, e.g. LAH in THF at −20° C. or Red-Al inToluene/THF at −50° C.

[0117] For the reaction of compound 6 to compound 7 the Arndt-Eistertreaction may be used (in case q=2: hydrolysis with NaOH in EtOH at roomtemperature followed by addition of (COCl)₂, cat DMF in CH₂Cl₂ at 0° C.to room temperature to give the corresponding acid chloride followed byreaction with trimethylsilyldiazomethane in THF/CH₃CN at 0° C. to roomtemperature to give the corresponding diazoethanone and rearrangement tothe methylester with silver benzoate in MeOH/THF at −25° C. to roomtemperature gave 7). For q=3 compounds of formula 6 are hydrolyzed (NaOHin EtOH at room temperature), followed by formation of the correspondingWeinreb amide (e.g. HClH₂NOMe/NMM, EDCI, HOBT) and conversion to analdehyde (LAH, −78 to −30° C. in THF). The obtained compound can beconverted by a Horner-Emmons reaction (e.g. (EtO)₂P(═O)CH₂COOEt, NaH inTHF) followed by reduction of the double bond and reduction of the ester(a) Mg in MeOH, (b) LAH in THF at −20° C.) and BOC replacement (e.g. (a)TFA in CH₂Cl₂−20° C. to room temperature, (b) NaHCO₃/EtOAc, (c)ClCOOR³/Et₃N or conversion to all other R³X described later).

[0118] For the introduction of Y═NR², SR² or a N-heterocycle (step g) acompound of formula 8 or 9 may be mesylated (1.1 eq MeSO₂ Cl/1.5pyridine/1 eq DMAP; in case Y is an amine the reaction is performed withe.g. 1 eq NaI, amine neat 100° C., for Y R² is pyrrole, imidazole or Xis S, the reaction is performed with 1 eq NaI, NaH in DMF at 0° C. toroom temperature, followed by thiol deprotection, e.g. by treatment withTFA/Et₃SiH, 0° C. to room temperature (R¹ is Trt) or TFA/Et₃SiH, 0 to80° C. (R¹ is PMB). An alternative method for the introduction of Y═NR²would comprise the reaction of compound 8 or 9 with 1.1 eq MeSO₂Cl/1.5eq pyridine/1 eq DMAP (mesylation) followed by treatment with NaN₃, DMFfor 16 hours at 80° C. to obtain the azide. This compound is thenconverted to the Y═NR² (=amines or triazoles) after the introduction ofnew R³X.

[0119] For the introduction of a new R³X in case R³X is BOC, the azidemay be BOC deprotected by reaction with TFA, CH₂Cl₂ at −20° C. to roomtemperature, followed by reaction with ClCO₂R³, iPr₂NEt, CH₂Cl₂ or R³NCOin THF at 0° C. to room temperature (or conversion to all other R³Xdescribed later), followed by reduction of the azide (e.g. Ph₃P, THF,H₂O or NaBH₄, MeOH), followed by reductive amination (e.g. aldehyde,SnCl₂, NaBH₃CN, MeOH). In case R⁶ has to be introduced the compound istreated with R⁶Br/K₂CO₃ in acetonitrile at room temperature followed bythiol deprotection (e.g. Et₃SiH, TFA, 0° C. to room temperature orEt₃SiH, TFA, MeCN at room temperature or, for selective trityl-thioldeprotection in the presence of BOC by for example treatment withiPr₃SiH in TFA/CH₂Cl₂, 0° C. to room temperature).

[0120] A further method for the introduction of new substituents YR² andXR³ comprises the oxidation of an alcohol 8 or 9 to the aldehyde (e.g.with (COCl)₂/DMSO/iPr₂NEt at −65° C. to room temperature in CH₂Cl₂), animine formation (e.g. corresponding primary amine/MgSO₄, roomtemperature, 16 hours in CH₂Cl₂), reduction to the amine (e.g. NaBH₄ inMeOH at 40° C., FMOC-protection of Y═NHR² (e.g. FMOC-Cl/iPr₂NEt/catDMAP, 0° C. to room temperature), BOC-deprotection (e.g. TFA in CH₂Cl₂,0° C. to room temperature), followed by reaction with R³NHSO₂Cl (in e.g.iPr₂NEt, 0° C. to room temperature) (or conversion to all other R³Xdescribed later), FMOC-deprotection (e.g. Et₂NH in THF), and thioldeprotection (e.g. Et₃SiH in TFA at 80° C.).

[0121] Compounds wherein YR2 is triazol may be prepared via step g byreaction of the above mentioned azide with the correspondingalkyl/amineCOCH₂ keton/ester/amide/aryl and K₂CO₃ (in DMSO, 40° C. for 3days) followed by thiol deprotection (e.g. Et₃SiH, TFA, 0° C. to roomtemperature or Et₃SiH, TFA, MeCN, room temperature). An alternative isthe reaction of the corresponding azide with alkyl/amineCOCH₂ ester,K₂CO₃, DMSO, 40° C. for 3 days, followed by hydrolysis of the ester(e.g.LiOH, THF) and thiol deprotection as described above.

[0122] In case of an introduction of a new substituent R³X in case R³Xis BOC, the corresponding compound may be prepared via step g by BOCdeprotection (TFA, CH₂Cl₂, −20° C. to room temperature), followed byreaction with a compound of formula R³OCOCl and iPr₂NEt/CH₂Cl₂ orconversion to all other R³X described later.

[0123] In case YR² represents a phenolether the phenol may be introducedvia step g under Mitsunobu conditions (e.g. DEAD/Ph₃P/PhOH in THF) andin case R¹ is Trt followed by reaction with e.g. TFA/Et₃SiH at 0° C. toroom temperature or, in case R¹ is PMB, followed by reaction with e.g.TFA/Et₃SiH, at 0 to 80° C. In case YR² represents carbamates, thecorresponding compounds 5 may by obtained via step g by reaction withisocyanate/NMM in toluene at room temperature followed optionally byreaction with the corresponding alkyl-, cycloalkyl-halogenide,alkylbromoacetate with NaH in DMF at 0° C. to room temperature. If YR²represents an ether the corresponding compounds 5 may be obtained viastep g by O-alkylation (e.g. NaH, R²-halogenide, DMF 0° C. to roomtemperature) or by O-alkylation with phase transfer conditions (e.g.R²-halogenide/50% NaOH, Bu₄NHSO₄). This reaction may be followed byreaction with e.g. TFA/Et₃SiH at 0° C. to room temperature (R¹ is Trt)or, in case R³ is PMB, followed by reaction with e.g. TFA/Et₃SiH, at 0to 80° C.

[0124] Compounds containing a group of formula (II) may be prepared viastep g by reaction of the corresponding starting compound 8 or 9 withNaH, R²-halogenide/NaI, DMF and in case R² contains a COOtBu (a)reaction with TFA in CH₂Cl₂ at −20° C. and (b) reaction with EDCI/HOBTamine in CH₂Cl₂ for formation of the corresponding amide—or, in case R²contains a COO-alkyl—(a) reaction with 1N NaOH in THF/EtOH to give theacid. Both pathways are completed by reaction with Et₃SiH in TFA at 0°C. to room temperature.

[0125] Compounds wherein YR² is an ether the group R³X may be varied asfollowed: For O-alkylation compounds of formula 8 or 9 may be reactedwith e.g. NaH/reactive R²Br in DMF at 0° C. to room temperature followedbe BOC deprotection (e.g. TFA in CH₂Cl₂ at −20° C. to room temperatureto get the amine as starting material.

[0126] In case R³X is a carbamate these starting compounds may bereacted with R³OCOCl/pyridine in THF or by reaction with (a)R³OH/Cl₃COCl/quinoline (formation of the chloroformate) followed byreaction with NaH. In case R³X is a sulfonamide the starting compoundsmay be reacted with R³SO₂Cl/(i-Pr)₂EtN/cat DMAP in ClCH₂CH₂Cl at roomtemperature. In case R³X is urea the starting compounds may be reactedwith isocyanate in EtOH at room temperature. In case R³X is an alkylatedurea, (i.e. introduction of R⁵) the starting compounds may be reactedwith isocyanate in EtOH at room temperature followed by reaction withthe corresponding alkylhalogenide/K-OtBu at 0° C. to room temperature.In case R³X is an amide, the starting compounds may be reacted withRCOOH/EDCI/DMAP (with anhydride formation, and subsequent addition ofthe starting amine, −10° C. to room temperature) or as alternative withRCOOH/EDCI/DMAP at room temperature. In case R³X is a sulfamide (for R³is NH₂) the starting compounds may be reacted with sulfamic acid2,4,6-trichlorophenylester/Et₃N in CH₂Cl₂ at 40° C. or with othermethods which are known in the art. In case R³X is SO₂OH the startingcompounds may be reacted with chlorosuphonic acid/2-picoline. In caseR³X is an alkylated sulfamide (i.e. introduction of R⁵) the startingcompounds may be reacted with NaH/alkyl halide in DMF at 0° C. at roomtemperature. Thiol liberation can than be achieved by reaction inTFA/Et₃SiH at room temperature.

[0127] Step h of scheme 1 includes a reaction pathway for thepreparation of further derivatives by reaction of compounds of formula 4with (a) NaH/reactive R²Br in DMF at 0° C. to room temperature followedby (b) reaction with KSAc in DMF at 100° C. The corresponding thiolscould be obtained by reaction of the the above compounds with LiOHaqueous in EtOH at 0° C. to room temperature.

[0128] Step i of scheme 1 shows the preparation of compounds of formula5 wherein Y is C. Compounds of formula 4 are treated with NaOH in EtOHat room temperature, followed by formation of a Weinreb amide (e.g. byreaction with HCl.H₂NOMe/NMM, EDCI, HOBT at 0° C. to room temperature),followed by formation of the corresponding ketone (e.g. by reaction withR²—MgBr in THF, at 0° C. to room temperature), BOC deprotection (e.g.TFA in CH₂Cl₂, at −20° C. to room temperature) followed by reaction withR³OCOCl/NMM in CH₂Cl₂ (or conversion to all other R³X described before)and reduction of the ketone to the methylene and thiol deprotection(e.g. Et₃SiH in TFA at 80° C. for 18 hours).

[0129] Further reaction pathways are shown in scheme 2: Compounds offormula 2 may be obtained by persilylation of the hydroxy- and aminogroups of compounds 1 (e.g. reaction with HMDS, neat 120° C.) andpreparation of the corresponding methyl ester (step a) (e.g. R³SO₂Cl,iPr₂NEt, THF, if acid, then e.g. MeOH, HCl). Step b of scheme 2 showsthe formation of the corresponding t-Butyldimethylsilylether or forexample the t-butylether (e.g. by reaction with TBDMSCI/DBU in CH₃CN at0° C. to room temperature, or by reaction with isobutylene, BF₃.OEt₂ inCH₂Cl₂ at −30 to −20° C. Step c comprises the reaction of compound 2with LiBH₄ in THF at −20° C. to room temperature or LAH at −15° C. inether to obtain compounds 4.

[0130] In case R²Y is R²N, step d of scheme 2 shows the introduction ofa phthalimide under Mitsunobu conditions (e.g. phthalimide, DEAD/Ph₃P inTHF, 3 to 80° C. This may be followed by t-butyldimethylsilyletherdeprotection (e.g. for t-BuMe₂Si: reaction with TBAF in THF at roomtemperature), followed by reaction with e.g. MeSO₃H/DIAD/Ph₃P in tolueneat room temperature −80° C., followed by e.g. reaction with KSCOCH₃ inDMF at 100° C., followed by phthalimide deprotection and disulfideformation (e.g. by reaction with CH₃NH₂, EtOH for 2 days at roomtemperature which may be followed by reaction with R²SO₂Cl or R²COCl,DMAP in CH₂Cl₂ or R²CO₂H, TPTU or N-alkylation by reaction with R²Br andN-methylmorpholine in CH₂Cl₂. This may be followed by side chainmanipulation e.g. hydrolysis with LiOH in THF/H₂O. Step e of scheme 2shows the reduction of the disulfide to the thiol (e.g. bynBu₃P/CF₃CH₂OH/H₂O at 0° C. or DTT, 2 M K₂CO₃, MeCN).

[0131] In case R²Y is R²O: Compounds of this type may be obtained byreaction shown in step f and g. These reaction may comprise (step f)reaction of compounds 4 with R²Br/NaH in DMSO at room temperature orbenzyl-2,2,2-trichloroacetimidate/CF₃SO₃H in CH₂Cl₂/cyclohexane at roomtemperature (here the R²-side chains may be manipulated by reaction with10% Pd/C/H₂ in EtOH/dioxane) or the reaction is performed withPhOH/Ph₃P/DIAD in THF at room temperature. All reactions may be followedby removal of the t-Bu-ether in TFA at 0° C. to room temperature. Forthe preparation of compounds of formula 7 (step g) compounds 6 (if m=0:for inversion of the configuration) may be obtained by thioacetateformation under Mitsunobu conditions (e.g. CH₃COSH/Ph₃P/DIAD in THF at0° C. to room temperature) followed by formation of the thiol (e.g. byreaction with MeONa in MeOH at 0° C.; plus potential side chainmanipulation with 1 N Na₂CO₃ in MeOH) or (if m=0: for retention ofconfiguration) reaction of compounds 6 for e.g. formation of themesylate (MeSO₃H/Et₃N/Ph₃P/DIAD in toluene at 0° C. to 85° C.) followedby preparation of the thioacetate (e.g. KSCOCH₃ in DMF at 100° C.) andformation of the thiol (MeONa in MeOH at 0° C.).

[0132] Scheme 3 shows a further route for the preparation of compoundsof formula (I). Step a comprises the preparation of compounds 2 byreaction of compounds 1 with e.g. R³SO₂C1/DMAP in CH₂Cl₂ at roomtemperature or Et₃N in CH₂Cl₂ (reflux)) followed by monohydrolysis (e.g.1 M NaOH in MeOH/H₂O for 20 min reflux and reduction of the acid withe.g. BH₃.THF in THF at 0° C. Step c shows an alkylation (e.g. withR²Br/NaH in DMSO at room temperature) followed by ester reduction (e.g.LAH at −15° C. in ether). Step e comprises the formation of thethioacetate (e.g. by CH₃COSH/Ph₃P/DIAD in THF at 0° C. to roomtemperature followed by formation of the thiol (e.g. with MeONa in MeOHat 0° C. Step f shows the reduction of both esters (e.g. with LAH in THFat 0° C.) followed by monoalkylation (e.g. with R²Br/NaH in DMF at −15°C., step g). This pathway may be continued by formation of the mesylate(e.g. with MeSO₂Cl/Et₃N in Et₂O at −20° C. to room temperature),formation of the thioacetate (e.g. with KSCOCH₃ in DMF at 100° C.) andformation of the thiol (LAH in Et₂O reflux). Step h depicts anadditional way for preparing a mono-p-tosylate (e.g. withp-TosCl/Et₃N/cat DMAP in THF at room temperature) followed byintroduction of the tritylthiolate (e.g. with Ph₃CSH/KOt-Bu in DMF atroom temperature), formation of the mesylate (step i, with MeSO₂Cl/Et₃Nin THF at 0° C. to room temperature) followed by the formation of thephenolether (e.g. with PhOH/NaH in DMF at room temperature) oralternatively alkylation of the alcohol directly with R²Br/NaH in DMF at−15° C. to room temperature and finally formation of the thiol (e.g.with Et₃SiH in TFA at 0° C. to room temperature).

[0133] Scheme 4 shows in step a the selective protection of the thiolgroup (e.g. by reaction with Ac₂O/pyridine in CH₂Cl₂ at roomtemperature; the starting compound can be received by a deprotection ofa STrt or SPMB protected alcohol described above, e.g. Et₃SiH in TFA).The S-acetylated alcohol was then reacted with (a)1,2,3,4-tetra-O-acetyl-t-deoxy-beta-L-mannospyranose/trimethylsilyl-trifluoromethanesulphonatein CH₂Cl₂ at 0° C. followed by cleavage of all acetyl group with NaOMein MeOH at 0° C.

[0134] Scheme 5 shows the reaction pathway for the synthesis ofsterically hindered thiols. Step a represents a Swern-oxidation of thestarting material which is known in the art (e.g.(COCl)₂/DMSO/Et(i-Pr)₂N in CH₂Cl₂). Step b shows the methyleneintroduction by a Wittig reaction (e.g. with Kt-BuO/CH₃PPh₃Br in THF atroom temperature to 70° C. Step c shows a reduction via a mixedanhydride (e.g. with iBuOCOCl/NMM in THF at −5° C. to room temperature,then the mixture is added to NaBH₄ in water at 0° C. and warmed up toroom temperature) followed by alkylation of the corresponding alcohol(e.g. with NaH/R²Br in THF at 0° C. to room temperature). Step drepresents the formation of an epoxide (e.g. with mCPBA in CH₂Cl₂ atroom temperature) followed by the formation of a thiirane (e.g. withKSCN in EtOH/H₂O at room temperature or PO(OMe)₂SCl in CH₂Cl₂). Theresulting diastereomers are separable with methods known in the art.Step e shows the opening of the thiirane (e.g. with LiHBEt₃ in THF andLAH) and reduction of the resulting disulfide (e.g. with P(Bu)₃/H₂O intrifluoroethanol/CH₂Cl₂).

[0135] Scheme 6 shows the synthesis of further derivatives: for Y beingNH: Step a comprises the N-acylation (protection of NH, e.g. with AcCl,iPr₂NEt, 4-(N-benzyl-N-methylamino)pyridine polymer-supported, CH₂Cl₂)or by N-CBz-Protection (e.g. with BnOCOCl, iPr₂NEt,4-Benzyl-N-methylamino)pyridine polymer supported, CH₂Cl₂), followed byselective BOC deprotection (e.g. with TFA, CH₂Cl₂ at −20° C. to roomtemperature) and reaction with a reactive R³ derivative (e.g. R³CO₂Cl,iPr₂NEt, 4-(N-Benzyl-N-methylamino)pyridine polymer-supported, CH₂Cl₂;step c(or conversion to all other R³X described before)) and formationof the thiol (e.g. with iPr₃SiH, TFA, CH₂Cl₂).

[0136] For Y being C-, protected-N-, O- or S-substituents step e ofscheme 6 shows formation of S-compounds of thiol inhibitors of formula(I) by (a) reaction of the free thiol with for example AcCl in pyridineor PhCOCl in pyridine at 0° C. to room temperature or (b) a S-derivativesynthesis (e.g. withBOC-Cys(Npys)-OH=2-(BOC-Cys)disulfanyl-3-nitro-pyridine orAc-Cys(Npys)-OH=2-(acetyl-Cys)disulfanyl-3-nitro-pyridine) in DMF/0.1 Mphosphate buffer (pH 6.2). The reaction for Y being protected N-atoms (Ydeprotection) can be performed selective with for example HBr/AcOH inEtOAc. Step f shows the formation of the thiol as described above.

[0137] The present invention also refers to the above describedprocesses, especially to processes for the preparation of a compound ofthe present invention comprising reaction of a compound of formula V

[0138] wherein R¹, R³, R⁴, X, Y, m, n, o, q and p are as defined aboveand A is a HS-protecting group

[0139] a) with a R²-halogenide for introduction of a —OR² group: or

[0140] b) mesylation of a compound of formula (V), followed by reactionwith H R6N—R or HSR₂ or HN-heterocycles for introduction of a —NR⁶—R² or—SR² group or —N-heterocycle;

[0141] optionally followed by conversion of a R³—X group into adifferent oneand/or deprotection and/or thiol liberation.

[0142] Dimeric forms of a compound of formula I may be prepared byoxidative treatment of the formula I monomers.

[0143] On the basis of their capability of inhibiting metalloproteaseactivity, especially zinc hydrolase activity, the compounds of formula Ican be used as medicaments for the treatment and prophylaxis ofdisorders which are associated with vasoconstriction of increasingoccurrences. Examples of such disorders are high blood pressure,coronary disorders, cardiac insufficiency, renal and myocardialischaemia, renal insufficiency, dialysis, cerebral ischaemia, cardiacinfarct, migraine, subarachnoid haemorrhage, Raynaud syndrome andpulmonary high pressure. They can also be used in atherosclerosis, theprevention of restenosis after balloon-induced vascular dilation,inflammations, gastric and duodenal ulcers, ulcus cruris, gram-negativesepsis, shock, glomerulonephtritis, renal colic, glaucoma, asthma, inthe therapy and prophylaxis of diabetic complications and complicationsin the administration of cyclosporin, as well as other disordersassociated with endothelin activities.

[0144] The ability of the compounds of formula (I) to inhibitmetalloprotease activity, particularly zinc hydrolase activity, may bedemonstrated by a variety of in vitro and in vivo assays known to thoseof ordinary skill in the art. Pharmaceutically acceptable esters,pharmaceutically acceptable salts and dimeric forms of the compounds offormula I can also be tested by those of ordinary skill in the art fortheir ability to inhibit metalloprotease activity.

[0145] A) Cell Culture

[0146] A stable human umbilical vein endothelial cell line (ECV304) wascultured in “cell factories” as described until confluency (Schweizer etal. 1997, Biochem. J. 328: 871-878). At confluency cells were detachedwith a trypsin/EDTA solution and collected by low speed centrifugation.The cell pellet was washed once with phosphate buffered saline pH 7.0and stored at −80° C. until use.

[0147] B) Solubilization of ECE from ECV304 Cells

[0148] All procedures were performed at 0-4° C. if not stated otherwise.The cell pellet of 1×10⁹ cells was suspended in 50 ml of buffer A (20 mMTris/HCl, pH 7.5 containing 5 mM MgCl₂, 100 μM PMSF, 20 μM E64, 20 μMleupeptin) and sonicated. The resulting cell homogenate was centrifugedat 100,000 g_(av) for 60 minutes. The supernatant was discarded and theresulting membrane pellet was homogenized in 50 ml buffer A andcentrifugated as described. The washing of the membrane fraction inbuffer A was repeated twice. The final membrane preparation washomogenized in 50 ml of buffer B (buffer A+0.5% Tween 20 (v/v), 0.5%CHAPS (w/v), 0.5% Digitonin (w/v)) and stirred at 4° C. for 2 hours.Thereafter the remaining membrane fragments were sedimented asdescribed. The resulting clear supernatant containing the solubilizedECE was stored in 1.0 ml aliquots at −120° C. until use.

[0149] C) ECE Assay

[0150] The assay measured the production of ET-1 from human big ET-1. Tomeasure high numbers of samples an assay performed in 96 well plates wasinvented. The enzyme reaction and the radioimmunological detection ofthe produced ET-1 was performed in the same well, using a specificallydeveloped and optimized coating technique.

[0151] D) Coating of Plates

[0152] Fluoronunc Maxisorp White (code 437796) 96 well plates wereirradiated with 1 joule for 30 minutes in a UV Stratalinker 2400(Stratagene). The 96 well plates were then fill with 300 μl protein Asolution (2 μg/ml in 0.1 M Na₂CO₃ pH 9.5) per well and incubated for 48hours at 4° C. Coated plates can be stored for up to 3 weeks at 4° C.until use.

[0153] Before use the protein A solution is discarded and the plates areblocked for 2 hours at 4° C. with 0.5% BSA in 0.1M Na₂CO₃, pH 9.5.

[0154] Plates were washed with bidestilled water and were ready toperform the ECE assay.

[0155] E) Screening Assay

[0156] Test compounds are solved and diluted in DMSO. 10 μl of DMSO wasplaced in the wells, followed by 125 μl of assay buffer (50 mM Tris/HCl,pH 7.0, 1 μM Thiorphan, 0.1% NaN₃, 0.1% BSA) containing 200 ng big ET-1.The enzyme reaction was started by the addition of 50 μl of solubilizedECE (diluted in assay buffer 1:30 to 1:60 fold (v/v)). The enzymereaction was carried out for 30 minutes at 37° C. The enzyme reactionwas stopped by addition of 10 μl 150 mM ETDA, pH 7.0.

[0157] F) Radioimmunoassay

[0158] The ET-1 RIA was performed principally as described earlier(Loffler, B.-M. and Maire, J.-P. 1994, Endothelium 1: 273-286). Toplates containing the EDTA stopped enzyme reaction mixture 25 μl ofassay buffer containing 20000 cpm (3-(¹²⁵I)Tyr)-endothelin-1 and 25 μlof the ET specific antiserum AS-3 (dilution in assay buffer 1:1000) wasadded. Plates were incubated under mixing at 4° C. over night.Thereafter, the liquid phase was sucked with a plate washer and plateswere washed once with bidestilled water. To the washed plates 200 μlscintillation cocktail (Microscint 40 LSC-Cocktail, Packard, code6013641) was added and plates were counted for 2 minutes per well in aTopcount.

[0159] Standard curves were prepared in plates with synthetic ET-1 withfinal concentrations of 0 to 3000 pg ET-1 per well. In all platescontrols for maximal ECE activity (in the presence of 10 μl DMSO) andfor background production of ET-1 immunoreactivity (in the presence of10 mM EDTA or 100 μM phosphoramidon) were performed. Assays were run intriplicate.

[0160] G) Kinetic Assay

[0161] The described assay format could be used to determine the kineticcharacteristics of the used ECE preparation as well as different ECEinhibitors (i.e. Km, Ki) by variation of the substrate concentrationused in the assay.

[0162] H) Cell Based ECE Assay

[0163] Human ECE-1c was stable expressed in MDCK cells as described(Schweizer et al. 1997, Biochem. J. 328: 871-878). Cells were culturedin 24 well plates to confluency in Dulbecco's modified Eagles'smedium(DMEM) supplemented with 10% (v/v) fetal bovine serum (FBS), 0.8mg/ml geneticin, 100 i.u./ml penicillin and 100 μg/ml streptomycin in ahumidified air/CO₂ (19:1) atmosphere. Before ECE assay the medium wasreplaced by 0.5 ml DMEM-HBSS 1:1, 10 mM HEPES pH 7.0 supplemented with0.1% (w/v) BSA. The inhibitors were added in DMSO at a finalconcentration of 1%. The enzyme reaction was started by the addition of0.42 μM human big ET-1 and performed for 1.5 hours at 37° C. in anincubator. At the end of incubation, the incubation medium was quicklyremoved and aliquots were analysed by radioimmunoassay for produced ET-1as described above.

[0164] The ECE screening assay was validated by the measurement of thecharacteristic inhibitor constants of phosphoramidon (IC₅₀ 0.8±0.2 μM)and CGS 314447 (IC₅₀ 20±4 nM) [De Lombaert, Stephane; Stamford, Lisa B.;Blanchard, Louis; Tan, Jenny; Hoyer, Denton; Diefenbacher, Clive G.;Wei, Dongchu; Wallace, Eli M.; Moskal, Michael A.; et al. Potentnon-peptidic dual inhibitors of endothelin-converting enzyme and neutralendopeptidase 24.11. Bioorg. Med. Chem. Lett. (1997), 7(8), 1059-1064].All three inhibitors were measured with IC₅₀ values not significantlydifferent from those described in the literature but measured withdifferent assay protocols. In the cell based assay phosphoramidon showedan IC₅₀ of 4 μM. This assay gave additional information about theinhibitory potency of inhibitors under much more physiologic conditions,as e.g. the ECE was embedded in a normal plasma membrane environment. Itis important to state, that the screening assay was performed in thepresence of 1 μM Thiorphan to block any potential big ET-1 degradationdue to the action of NEP24.11. No NEP activity was present inMDCK-ECE-1c transfected cells in preliminary experiments when ET-1production was measured in presence or absence of thiorphan. Insubsequent experiments no thiorphan was added in the incubation medium.

[0165] According to the above methods, the compounds of the presentinvention show activity values in the radioimmunoassay (E and F) ofabout 0.5 nM to about 100 μM. The preferred compounds show values of 0.5nM to 100 nM.

[0166] As mentioned earlier, medicaments containing a compound offormula I are also an object of the present invention as is a processfor the manufacture of such medicaments, which process comprisesbringing one or more compounds of formula I and, if desired, one or moreother therapeutically valuable substances into a galenicaladministration form.

[0167] The pharmaceutical compositions may be administered orally, forexample in the form of tablets, coated tablets, drages, hard or softgelatin capsules, solutions, emulsions or suspensions. Administrationcan also be carried out rectally, for example using suppositories;locally or percutaneously, for example using ointments, creams, gels orsolutions; or parenterally, for example using injectable solutions.

[0168] For the preparation of tablets, coated tablets, dragees or hardgelatin capsules the compounds of the present invention may be admixedwith pharmaceutically inert, inorganic or organic excipients. Examplesof suitable excipients for tablets, dragees or hard gelatin capsulesinclude lactose, maize starch or derivatives thereof, talc or stearicacid or salts thereof.

[0169] Suitable excipients for use with soft gelatin capsules includefor example vegetable oils, waxes, fats, semi-solid or liquid polyolsetc. According to the nature of the active ingredients, it may, however,be the case that no excipient is needed at all for soft gelatincapsules.

[0170] For the preparation of solutions and syrups, excipients which maybe used include for example water, polyols, saccharose, invert sugar andglucose. For injectable solutions, excipients which may be used includefor example water, alcohols, polyols, glycerin, and vegetable oils. Forsuppositories, and local or percutaneous application, excipients whichmay be used include for example natural or hardened oils, waxes, fatsand semi-solid or liquid polyols.

[0171] The pharmaceutical compositions may also contain preservingagents, antioxidants, solubilising agents, stabilizing agents, wettingagents, emulsifiers, sweeteners, colorants, odorants, salts for thevariation of osmotic pressure, buffers, coating agents or antioxidants.They may also contain other therapeutically valuable agents.

[0172] The dosages in which the compounds of formula I are administeredin effective amounts depend on the nature of the specific activeingredient, the age and the requirements of the patient and the mode ofapplication. In general, dosages of 0.1-100 mg/kg body weight per daycome into consideration, although the upper limit quoted can be exceededwhen this is shown to be indicated.

[0173] The following specific examples are provided as a guide to assistin the practice of the invention, and are not intended as a limitationon the scope of the invention.

EXAMPLES

[0174] All reactions are done under argon.

[0175] A) Abbreviations:

[0176] EtOAc ethylacetate, EtOH ethanol, THF tetrahydrofurane, Et₂Odiethylether, MeOH methanol, CH₂Cl₂ dichloromethane, EDCIN-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride, HOBT1-Hydroxybenzotriazole, DBU 1,8-Diazabicyclo[5.4.0]undec-7-ene(1,5-5),LAH Lithium aluminum hydride, LDA lithium diisopropylamide, DEAD Diethylazodicarboxylate, DIAD Diisopropyl azodicarboxylate, DMAP4-Dimethylaminopyridine, TBAF tetrabutylammonium fluoride, iPr₂NEtN-ethyldiisopropylamine, Ph₃P triphenylphosphine, P(Bu)₃tributylphosphine, Red-Al solutionNatrium-dihydrido-bis-(2-methoxyethoxy)-aluminat-solution, NMMN-methylmorpholine, Et₃N triethylamine,Cl₃COCl=di-phosgene=trichloromethyl-chloroforamate, PMBp-methoxy-benzyl, Trt trityl=Ph₃CSH, DTT 1,4-Dithio-DL-threitol,BOC-Cys(Npys)-OH 2-(BOC-Cys)disulfanyl-3-nitro-pyridine, Ac-Cys(Npys)-OH2-(acetyl-Cys)disulfanyl-3-nitro-pyridine.

[0177] B) General Method for a Selective BOC-Deprotection:

[0178] A solution of 15.1 mmol N-BOC-S-Trityl compound in 30 ml CH₂Cl₂was treated at −20° C. with 34 ml TFA and warmed up to room temperatureduring 5.5 h. The reaction was evaporated and treated with aqueoussaturated NaHCO₃ solution/EtOAc (3×) to give the freeaminotritylsulfanyl.

[0179] C) General Method for EDCI-Coupling:

[0180] Weinreb-amide formation: A solution of 13.6 mmol carboxylic acidin 150 ml CH₂Cl₂ was treated at 0° C. with 95.2 mmol N-methylmorpholine,0.37 g (2.72 mmol) HOBT, 6.26 g (32.64 mmol) EDCI and 2.92 g (29.92mmol) N,O-dimethylhydroxyl-amine hydrochloride. The reaction was stirredover night at room temperature and partitioned between aqueous 10%KHSO₄/EtOAc (3×). The organic phases were washed with aqueous saturatedNaCl and dried over Na₂SO₄. Purification by flash-chromatography onsilica gel (Hexane/EtOAc 1:1) gave of methoxy-methyl-carbamoylderivative.

[0181] D) General Method for Ester Hydrolysis:

[0182] A solution of 5.38 mmol carboxylic acid methyl ester wasdissolved in 150 ml EtOH and treated at RT with 10.8 ml (10.8 mmol)aqueous 1 N NaOH. After 3 h the reaction was evaporated and poured intoaqueous 10% KHSO₄/EtOAc (3×). The organic phases were washed withaqueous 10% NaCl solution and dried over Na₂SO₄ to give the carboxylicacid.

[0183] E) General Method for S-Deprotection:

[0184] Method 1: TFA/triethylsilane deprotection for labilep-methoxy-benzylsulfanyl compounds: A solution of 0.15 mmolp-methoxy-benzylsulfanyl was dissolved in 2 ml TFA, cooled to 0° C. andtreated with 0.24 ml (1.5 mmol) triethylsilane, stirred for 22 h at roomtemperature (the reaction was followed by TLC, if necessary treatedagain with 0.24 ml (1.51 mmol) triethylsilane and stirred for 30 h). Theevaporated residue was purified by flash silica gel column to give thethiol compound.

[0185] Method 2: TFA/triethylsilane deprotection for not labilep-methoxy-benzylsulfanyl compounds: A solution of 0.25 mmolp-methoxy-benzylsulfanyl and 0.4 ml (2.5 mmol) triethylsilane was heatedfor 1 min −1.5 h at 80° C. (followed by TLC), cooled to RT andevaporated. Crystallization from Et₂O/pentane gave the thiol-compound.

[0186] Method 3: Trityl deprotection for single compound: A solution of0.58 mmol tritylsulfanyl in 5.8 ml TFA was treated at 0° C. with 0.92 ml(5.78 mmol) triethylsilane and after 10 min at room temperatureevaporated and purified by flash chromatography on silica gel(Hexane/EtOAc 4:1) to give the thiol-compound.

[0187] Method 4: Trityl deprotection for parallel synthesis: A solutionof 0.32 mmol trityl-protected compound was dissolved in 1.5 mlacetonitril/0.4 ml TFA/0.1 ml triethylsilane and after 1 night at roomtemperature purified by preparative HPLC (RP18, CH₃CN/H₂O 80:20 to 95:5)to give the free thiols.

[0188] Method 5: Trityl deprotection in the presence of BOC: 1 eqTrityl-protected compound in CH₂Cl₂ (15-20 ml/mmol) was treated with 10eq triisopropyl silane and 10 eq TFA at 0° C. or RT until no startingmaterial could be detected. The solution was poured on saturated NaHCO₃solution and the inorganic phase was extracted with CH₂Cl₂, the organicphases were washed with brine, dried over Na₂SO₄ and evaporated andpurified by flash chromatography to give the free amine.

Example 1 Starting Materials Example 1.a

[0189] Alcohols: 40 g (220 mmol) of L-hydroxyproline methylesterhydrochloride (twice suspended in toluene and evaporated under reducedpressure to remove water) was suspended in 600 ml hexamethyldisilazaneand refluxed for 2 h. The solution was evaporated under reduced pressureand dissolved in 100 ml THF. 49.9 g (220 mmol) of2-naphthalene-sulphonyl chloride in 200 ml of THF were added slowly andstirred for 16 h at room temperature. 150 ml H₂O were added and after 1h the solvents were evaporated. The residue was partitioned betweenwater/EtOAc (3×), the organic phases were washed with 10% NaCl and driedover Na₂SO₄ to give 60.4 g (82%) of(2S,4R)-4-hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid methyl ester, MS: 335 (Me).

[0190] The following compounds were prepared in an analogous manner:

[0191] L-hydroxyproline benzylester hydrochloride and1-naphthalenesulfonyl chloride gave(2S,4R)-4-hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid benzyl ester, MS: 411 (MH⁺);

[0192] L-hydroxyproline benzylester hydrochloride and methanesulfonylchloride gave(2S,4R)-4-hydroxy-1-methanesulfonyl-pyrrolidine-2-carboxylic acid benzylester, mp 132-133° C., MS: 300 (MH⁺);

[0193] L-hydroxyproline methylester hydrochloride and methanesulfonylchloride gave after extraction with CH₂Cl₂(2S,4R)-4-hydroxy-1-methanesulfonyl-pyrrolidine-2-carboxylic acid methylester, mp 115.5-117° C., MS: 164 (M-COOMe.).

Example 1.b

[0194] Via Mesylate: A biphasic solution of 13.9 ml (215 mmol)methanesulfonic acid,

[0195] 29.8 ml (215 mmol) triethylamine and 58.7 g (224 mmol)triphenylphosphine in 150 ml toluene was added to a suspension of 60 g(179 mmol)(2S,4R)-4-hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid methyl ester in 300 ml toluene which was stirred mechanically.After adding 44.9 ml (233 mmol) of diisopropyl azodicaboxylate(exothermic!) the solution was heated for 2.5 h at 80° C. 300 ml waterwas added at room temperature and extracted with EtOAc (3×300 ml). Theorganic phase was washed with aqueous 10% KHSO₄ (2×100 ml), 10% NaCl(2×150 ml) dried over Na₂SO₄ and evaporated to give 180 g of crudeproduct. Flash chromatography (EtOAc/hexane 1:1) gave 63.7 g (86%) of(4S,2S)-4-methanesulfonyloxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid methylester.

[0196] 64.2 g (167 mmol) of triphenylmethanthiol was slowly added atroom temperature to a solution of 17.9 g (160 mmol) of potassiumtert-butylate in 300 ml DMF and stirred mechanically for 30 min. Then 63g (152 mmol) of(4S,2S)-4-methanesulfonyloxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid methylester in 300 ml DMF were added at 20° C. by cooling at theend with an ice bath. The reaction was heated for 1.3 h at 100° C.,cooled, evaporated to 400 ml and extracted with 250 ml aqueous saturatedNH₄Cl/EtOAc (3×300). The organic phases were washed with aq. 10% NaCl,dried (Na₂SO₄) and evaporated. Flash chromatography (CH₂Cl₂/MeOH 99:1)gave 58.6 g (65%, (2S,4R)/(2R,4R)-isomer ca 4:1, 1H-NMR) and 9.2 g (10%,(2S,4R)/(2R,4R)-isomer ca 1:1, ¹H-NMR) of(2S,4R)-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidine-2-carboxylicacid methyl ester, MS: 594 (MH⁺).

[0197] The following compounds were prepared:

[0198] (2S,4R)-4-hydroxy-1-methanesulfonyl-pyrrolidine-2-carboxylic acidmethyl ester gave after 3.75 h at 80° C.(4S,2S)-4-methanesulfonyloxy-1-(methylsulfonyl)-pyrrolidine-2-carboxylicacid methylester which was heated for 45 min at 100° C. withtriphenyl-methanthiolate to give(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidine-2-carboxylic acidmethyl ester (2S,4R)/(2R,4R)-isomer ca 9:1, ¹H-NMR), MS: 482 (MH⁺);

[0199] (2S,4R)-4-hydroxy-1-methanesulfonyl-pyrrolidine-2-carboxylic acidbenzyl ester gave after 5 h at 80° C.(2S,4S)-1-methanesulfonyl-4-methanesulfonyloxy-pyrrolidine-2-carboxylicacid benzyl ester which was heated for 30 min with4-methoxybenzylthiol/potassium tert-butylate to give(2S,4S)-1-methanesulfonyl-4-methanesulfonyloxy-pyrrolidine-2-carboxylicacid benzyl ester, mp 91-92° C., MS: 453 (M+NH₄ ⁺).

Example 1.c

[0200] Via bromid: To a solution of 76.5 g (291.6 mmol, 6 eq)triphenylphosphine in 650 ml THF were added 44.6 ml (286.8 mmol, 5.9 eq)DEAD in 70 ml THF at a temperature between 1.5-4.5° C. over a period of0.5 h. The solution was stirred for 0.5 h before 42.2 g (486.1 mmol, 10eq) LiBr were added, and the reaction mixture was recooled to 4° C. forthe addition of 20 g (48.6 mmol)(2S,4R)-4-hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid benzyl ester in 75 ml THF. After stirring at room temperature for 3h, water was added and the suspension concentrated and redissolved in700 ml EtOAc and water. The layers were separated, the inorganic one wasextracted with 100 ml of EtOAc (3×), and the combined organic layerswere washed with brine, dried over MgSO₄ and evaporated.Triphenylphosphine oxide was removed by crystallization fromEtOAc/hexane and the mother liquid was purified by colum chromatographyon silica gel with hexane: EtOAc 3:1 yielding 13.4 g (62%) of(2S,4S)-4-bromo-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylic acidbenzyl ester as colorless solid, mp 97-98° C., MS: 473 (MH⁺).

[0201] 3.38 g (30.1 mmol, 1.1 eq) potassium tert. butylate in 150 ml DMFwere treated with 4.4 ml (31.5 mmol, 1.15 eq) 4-methoxybenzyl mercaptaneat 0° C. The solution was stirred for 1 h at RT before 12.99 g (27.4mmol)(2S,4S)-4-bromo-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylic acidbenzyl ester in 100 ml DMF were added. The reaction was stirred at roomtemperature overnight, DMF was removed under vacuum, and the residueredissolved in EtOAc and 1M aqueous KHSO₄. The layers were separated,and the organic one washed with brine, dried over Na₂SO₄ and evaporated.The crude oil was purified by flash chromatography on silica gel withhexane/EtOAc (3:1-2:1) as eluent yielding 7.23 g (48%)(2S,4R)-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid benzyl ester as light yellow solid, mp 90-91° C., MS: 547 (M⁺).

[0202] The following compounds were prepared:

[0203] (2S,4R)-4-hydroxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butylester 2-methyl ester with 4-methoxybenzylthiol potassium tert-butylategave (2S,4R)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1,2-dicarboxylicacid 1-tert-butyl ester 2-methyl ester, MS: 382 (MH⁺).

Example 1.d

[0204] Via chloride: A solution of 374 g (1.48 mol)(2S,4R)-4-hydroxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester2-methyl ester in 1.61 CH₂Cl₂ was treated with 680 g (2.6 mol)triphenylphosphine, cooled to 3-5° C. and treated in 10 min with 1.241(12.8 mol) CCl₄, after 2 h at this temperature cooling was stopped, thereaction temperature was raised during 2 h to 35° C. It was cooled downto 20° C. and stirred for further 45 min. After addition of 4 l ofn-heptane, the reaction was evaporated to 2.9 l, cooled to 0° C.,filtered, the residue was treated twice the same way, the third time bydissolving the residue again in 2 l of CH₂Cl₂. The solvents wereevaporated and filtered through silica gel withhexane/tert.-butyl-methylether 9:1 as eluent. Evaporation of thesolvents gave 347 g (89%) of(2S,4S)-4-chloro-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester2-methyl ester, MS: 246 (MH⁺).

[0205] A solution of 76 g (0.68 mol) potassium-tert.-butylate in 1.5 lDMF was cooled (−3° C.) and treated slowly (1.5 h) with 202 g (0.73 mol)triphenylmethanethiole in 0.8 l DMF (at max 1° C.). After 2.5 h at 0°C., a solution of 161 g (0.61 mol) of(2S,4S)-4-chloro-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester2-methyl ester in 0.35 l DMF was added. The reaction was stirred overnight at 2° C., evaporated, dissolved in 1.5 l EtOAc, poured into 2.71aqueous saturated NH₄Cl solution and extracted with EtOAc (2×). Theorganic phase was washed with aqueous saturated NaHCO₃, dried overNa₂SO₄ and evaporated. Column chromatography on silica gel withhexane/EtOAc (95:5 to 7:3) gave 268 g (87%)(2S,4R)-4-tritylsulfanyl-pyrrolidine-1,2-dicarboxylic acid 1-tert-butylester 2-methyl ester, MS: 504 (MH⁺).

Example 1.e

[0206] Ester reduction, Method A: 57 ml (57 mmol, 1M THF solution) ofLAH was added during 15 min to a cold solution (−20° C.) of 28.2 g (47.5mmol, ca. (2S,4R)/(2R,4R)-isomer ca 4:1)(2S,4R)-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidine-2-carboxylicacid methyl ester in 460 ml THF. The reaction was stirred for 20 min,cooled to −78° C. and quenched with a suspension of 15 g silica gel/15 gMgSO₄ 7H₂O in 60 ml aqueous 10% KHSO₄. The suspension was stirred for 15min at room temperature, filtered and washed with THF. After evaporationof the THF, the residue was taken up in CH₂Cl₂, dried over Na₂SO₄ andevaporated to give 29.2 g crude product. Flash column chromatography onsilica gel with CH₂Cl₂₁EtOAc(2.5%) to CH₂Cl₂/EtOAc(10%) gave 21.7 g(81%) of(2S,4R)-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-methanoland 1.0 g (4%) of[(2R,4R)-4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanol,MS: 566 (MH⁺).

[0207] The following compounds were prepared:

[0208](2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidine-2-carboxylic acidmethyl ester [(2S,4R)/(2R,4R)-isomer ca. 9:1] gave isomerically pure(2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-methanol,MS: 471 (M+NH₄ ⁺);

[0209](2S,4S)-1-methanesulfonyl-4-methanesulfonyloxy-pyrrolidine-2-carboxylicacid benzyl ester gave(2S,4R)-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-methanol,MS: 331 (M);

[0210](2S,4R)-4-(4-Methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid benzyl ester gave(2S,4R)-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanolas colorless solid, mp 114-115° C., MS: 444 (MH⁺);

[0211] (2S,4R)-4-(4-Methoxy-benzylsulfanyl)-pyrrolidine-1,2-dicarboxylicacid 1-tert-butyl ester 2-methyl ester gave(2S,4R)-2-hydroxymethyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 252 (M-COOt-Bu);

[0212] (2S,4S)-4-Chloro-pyrrolidine-1,2-dicarboxylic acid 1-tert-butylester 2-methyl ester gave(2S,4S)-4-chloro-2-hydroxymethyl-pyrrolidine-1-carboxylic acidtert-butyl ester; MS: 162 (M-t-BuO).

Example 1.f

[0213] Ester reduction, Method B: A solution of 35 g (69 mmol)(2S,4R)-4-Tritylsulfanyl-pyrrolidine-1,2-dicarboxylic acid 1-tert-butylester 2-methyl ester in 380 ml toluene/60 ml THF was treated at −47° C.to −50° C. with 44 g (152 mmol) of a 70% solution of sodiumdihydrido-bis(2-methoxy-ethoxo)aluminate in toluene (3.5 M Red-Al intoluene). After 3 h at −50° C. and 1 h at −30° C. the solution waspoured into water (1 l) with 40 g of citric acid and extracted withEtOAc (2×). The organic phase was dried over Na₂SO₄ and evaporated.Column chromatography on silica gel with hexane/EtOAc (7:3) gave 23.0 g(69%) (2S,4R)-2-hydroxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 476 (MH⁺).

Example 1.g

[0214] Synthesis According to Podlech & Seebach, Liebigs Ann. (1995), 7,1217-28:

[0215] A solution of 3.0 g (5.38 mmol)(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidine-2-carboxylic acidmethyl ester was dissolved in 150 ml EtOH and treated at roomtemperature with 10.8 ml (10.8 mmol) aqueous 1 N NaOH. After 3 h thereaction was evaporated and poured into aqueous 10% KHSO₄/EtOAc (3×).The organic phases were washed with aqueous 10% NaCl solution and driedover Na₂SO₄ to give 2.43 g (97%) of(2S,4R)-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidine-2-carboxylicacid, mp 64-69° C., MS: 466 (M−H)⁻.

[0216] A solution of 25 g (93 mmol)(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidine-2-carboxylic acidin 265 ml CH₂Cl₂ at 0° C. was treated with 2 drops of DMF followed by 8ml (99 mmol) oxalylchloride. After 15 min at 0° C. the reaction wasstirred 2 h at room temperature, evaporated and dissolved in 260 mlTHF/CH₃CN 1:1. 58.5 ml (117 mmol) 2M trimethylsilyldiazomethane solutionin hexane was then added at 0° C. The reaction was stirred 16 h at roomtemperature, evaporated and poured in H₂O/EtOAc. The organic phase wasdried over Na₂SO₄, evaporated and purified by flash columnchromatography on silica gel with hexane/EtOAc (7:3 to 1:1) to give 12.4g (48%) of(2S,4R)-2-diazo-1-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethanone,MS: 509 (M+NH₄ ⁺).

[0217] In analogy to above,(2S,4R)-2-diazo-1-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-ethanonewas obtained from(2S,4R)-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidine-2-carboxylicacid (with 2.3 eq. Trimethylsilyl-diazomethane) in 57% yield, MS: 621(M+NH4⁺).

[0218] A solution of 12 g (24.4 mmol)(2S,4R)-2-diazo-1-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethanonein 96 ml MeOH/67 ml THF was cooled (−25° C.) and treated in the darkwith 0.62 g (2.7 mmol) silver benzoate in 13.9 ml (99.7 mmol)triethylamine. The reaction was warmed to room temperature and stirred 1h at RT, evaporated, extracted with H₂O/EtOAc and flash columnchromatography on silica gel with hexane/EtOAc (7:3) gave 8.7 g (72%) of(2R,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-acetic acidmethyl ester, MS: 496 (MH⁺).

[0219] In analogy to above,(2R,4R)-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-aceticacid methyl ester was obtained from(2S,4R)-2-diazo-1-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-ethanonein 72% yield, MS: 625 (M+NH₄ ⁺).

[0220] Following the procedure of ester reduction, Method A,(2R,4R)-(1-methane-sulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-aceticacid methyl ester gave(2R,4R)-2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethanol,MS: 468 (MH⁺).

[0221] Following the procedure of ester reduction, Method A,(2S,4R)-2-diazo-1-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-ethanonegave(2R,4R)-2-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-ethanol,MS: 580 (MH⁺).

Example 1.h

[0222] Further starting compounds: Hydrolysis (see General Method forhydrolysis of an ester) of(2S,4R)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1,2-dicarboxylic acid1-tert-butyl ester 2-methyl ester gave(2S,4R)-4-(4-Methoxy-benzylsulfanyl)-pyrrolidine-1,2-dicarboxylic acid1-tert-butyl ester, MS: (M−H)-366.

[0223] A solution of 5 g (13.6 mmol)(2S,4R)-4-(4-Methoxy-benzylsulfanyl)-pyrrolidine-1,2-dicarboxylic acid1-tert-butyl ester 20-5620 in 150 ml CH₂Cl₂ was treated with 10.5 ml(95.2 mmol) N-methylmorpholine, 0.37 g (2.72 mmol)1-hydroxybenzotriazole,

[0224] 6.26 g (32.64 mmol) EDCI and 2.92 g (29.92 mmol)N,O-dimethylhydroxylamine hydrochloride. The reaction was stirred overnight at room temperature and partitioned between aqueous 10%KHSO₄/EtOAc (3×). The organic phases were washed with aqueous saturatedNaCl and dried over Na₂SO₄. Purification by flash-chromatography onsilica gel (Hexane/EtOAc 1:1) gave 3.6 g (62%) of(2S,4R)-4-(4-methoxy-benzylsulfanyl)-2-(methoxy-methyl-carbamoyl)-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 411 (MH⁺).

[0225] A solution of 1.5 g (3.5 mmol)(2S,4R)-4-(4-methoxy-benzylsulfanyl)-2-(methoxy-7methyl-carbamoyl)-pyrrolidine-1-carboxylic acid tert-butyl esterdissolved in 15 ml was added to 4.2 ml (4.2 mmol, 1M THF solution) ofLAH in 50 ml THF at −78° C. The reaction was was warmed up to −30° C.,cooled to −78° C. and quenched with a suspension of 1.2 g silica gel/1.2g MgSO₄.7H₂O in 5 ml aqueous 10% KHSO₄. The suspension was stirred for15 min at room temperature, filtered and washed with THF. Afterevaporation of the THF, the residue was taken up in CH₂Cl₂, dried overNa₂SO₄ and evaporated to give 1.2 g (98%) of(2S,4R)-2-formyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 351 (M⁺).

[0226] A solution of 0.91 g (4.08 mmol) triethyl phosphonoacetate in 10ml THF was first treated with 0.18 g (4.08 mmol) 55% NaH and aftercooling (−78° C.) with 1.2 g (3.4 mmol)(2S,4R)-2-formyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester. The reaction was warmed up to room temperatureand stirred over night. The solution was cooled (0° C.) and treated with1 ml MeOH followed by 10 ml saturated aqueous Na/K-tartrate and after 10min with aqueous 10% NaHCO₃ solution. The aqueous phase was filtered,extracted (EtOAc 2×) and the organic phase was dried (Na₂SO₄),evaporated and purified on silica gel column (Hexane/EtOAc 9:1 to 7:3)to give 0.57 g (40%) of(2S,4R)-2-(2-ethoxycarbonyl-vinyl)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 422 (MH⁺).

[0227] In analogy to literature [Hudlicky, T.; Sinai-Zingde, G.;Natchus, M. G. Tetrahedron Lett. (1987), 28(44), 5287-90] a solution of0.35 g (0.84 mmol)(2S,4R)-2-(2-ethoxycarbonyl-vinyl)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester in 20 ml MeOH was treated with 0.122 g (5.04 mmol)magnesium and stirred at room temperature for 5 h. The reaction wasevaporated, suspended twice in EtOAc and filtered to give 0.38 g(quantitative) of(2R,4R)-4-(4-methoxy-benzylsulfanyl)-2-(2-methoxycarbonyl-ethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 410 (MH⁺).

[0228] Following the procedure of ester reduction, Method A,(2R,4R)-4-(4-methoxy-benzylsulfanyl)-2-(2-methoxycarbonyl-ethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester gave(2R,4R)-2-(3-hydroxy-propyl)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 382 (MH⁺).

[0229] Following the procedure for the BOC-deprotection (general methodfor a selective BOC-deprotection),(2R,4R)-2-(3-hydroxy-propyl)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester gave(2R,4R)-3-[4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-propan-1-ol,MS: 282 (MH⁺).

[0230] A solution of 615 mg (2.19 mmol)(2R,4R)-3-[4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-propan-1-ol and0.34 ml (2.40 mmol) triethylamine in 5 ml CH₂Cl₂ was cooled to −10° C.and treated slowly with 0.31 ml (2.29 mmol) butylchloroformate. After 20min at this temperature the reaction was extracted with cold (0° C.)aqueous 10% KHSO₄/Et₂O (3×). The organic phase was washed with aqueoussaturated NaHCO₃ dried over Na₂SO₄ and evaporated. Flash columnchromatography on silica gel with hexane/EtOAc (2:1 to 1:1) gave 340 mg(32%) of(2R,4R)-2-(3-butoxycarbonyloxy-propyl)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid butyl ester and 230 mg (28%) of(2R,4R)-2-(3-hydroxy-propyl)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid butyl ester, MS: 382 (MH⁺).

[0231] In analogy:(2S,4R)-2-Hydroxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidtert-butyl ester gave via(2S,4R)-(4-tritylsulfanyl-pyrrolidin-2-yl)-methanol,(2S,4R)-2-hydroxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidbutyl ester, MS: 476 (MH⁺).

Example 2 Amines (via Mesylate)

[0232] A solution of 14.14 g (25 mmol) of(2S,4R)-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-methanolin 300 ml CH₂Cl₂ was treated at 0° C. with 2.14 ml (27.7 mmol) methanesulfonylchloride, 3.02 ml (37.5 mmol) pyridine, 3.05 g (25 mmol) DMAPand stirred at room temperature for 4 h. The reaction mixture was pouredinto EtOAc/H₂O acidified with 1 N HCl. The organic phase was washed with10% aqueous NaCl, dried over Na₂SO₄ and evaporated to give 15.98 g (99%)of methanesulfonic acid(2S,4R)-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-ylmethylester, MS: 644 (MH⁺).

[0233] The following compounds were prepared in an analogous manner:

[0234](2S,4R)-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-methanolgave (2S,4R)-methanesulfonic acid1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethylester in 82%, MS: 410 (MH⁺).

[0235](2R,4R)-2-(3-hydroxy-propyl)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid butyl ester gave(2R,4R)-2-(3-methanesulfonyloxy-propyl)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid butyl ester, MS: 460 (MH⁺).

[0236](2R,4R)-2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethanolgave methanesulfonic acid(2R,4R)-2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethylester, MS: 563 (MH⁺).

[0237](2S,4R)-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanolgave methanesulfonic acid(2S,4R)-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethylester as white solid, mp. 127° C., MS:522(MH⁺).

[0238] (2S,4R)-2-hydroxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester gave(2S,4R)-2-methanesulfonyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester as white foam, MS: 554 (MH⁺);

[0239](2R,4R)-2-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-ethanolgave (2R,4R)-methanesulfonic acid2-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-ethylester as white foam, MS: 658 (MH⁺).

[0240](2R,4R)-3-[4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-propan-1-olgave with 2.2 equivalent, methansulfonylchloride and 2 equivalent DMAP(2R,4R)-methanesulfonic acid3-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-propylester, MS: 438 (MH⁺).

[0241] Method A: 200 mg (0.31 mmol) Methanesulfonic acid(2S,4R)-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-ylmethylester and 47 mg (0.31 mmol, 1.0 eq) sodium iodide were dissolved in 5 mlethyl isonipecotate, heated to 100° C. for 3 h and the excess of theamine was removed under vacuum. The resulting residue was dissolved inEtOAc and 5% aqueous NaHCO₃ solution, the layers were separated, theorganic one was extracted with water (3×) and washed with brine, driedover Na₂SO₄, and evaporated.

[0242] The crude material(2S,4R)-1-[1-(Naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-ylmethyl]-piperidine-4-carboxylicacid ethyl ester was dissolved in 6.5 ml acetonitrile and 3 ml TFA, 0.5ml (3.1 mmol) triethylsilane were added, and the reaction was stirred at40° C. for 3 h. 40 ml aqueous saturated NaHCO₃ solution were addedcarefully, the layers were separated and the inorganic one was extractedwith EtOAc. The organic layer was washed with water and brine, driedover Na₂SO₄ and evaporated. The residue was purified by flashchromatography on silica gel with EtOAc/hexane 1:2 yielding 45 mg (30%,2steps) of(2S,4R)-1-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-piperidine-4-carboxylicacid ethyl ester as colorless oil, MS: 463(MH⁺).

[0243] In a similar manner, but replacing ethyl isonipecotate (5 ml,100° C., 3 h) with piperidine (5 ml, 100° C., 2 h), aniline (4 ml, 100°C., 12 h), benzylamine (4 ml, 100° C., 8 h), 2-fluorobenzylamine (2 ml,100° C., 8 h), N-benzylmethylamine (4 ml, 100° C., 8 h), diethylamine (4ml, 100° C., 8 h), 2,4-difluoro benzylamine (3 ml, 100 C, 8 h),2,5-difluorobenzylamine (3 ml, 100° C., 8 h),N-ethyl-o-fluorobenzylamine (3 ml, 100° C., 12 h),2,3-difluorobenzylamine (3 ml, 100° C., 12 h), 2,3,5-triflorobenzylamine(2 ml, 100° C., 12 h), 2,3,6-trifluorobenzylamine (2 ml, 100° C., 12 h),N-methyl-2-phenyl-ethylamine (4 ml, 100° C., 2 h), phenethylamine (4 ml,100° C., 2 h), i) dibenzylamine (4 ml, 100° C., 12 h.

[0244] The following compounds were prepared:

[0245](3R,5S)-1-(naphthalene-2-sulfonyl)-5-piperidin-1-ylmethyl-pyrrolidine-3-thiolas white solid, mp 90° C., MS: 391 (MH⁺);

[0246](3R,5S)-1-(naphthalene-2-sulfonyl)-5-phenylaminomethyl-pyrrolidine-3-thiolas orange oil, MS: 399 (MH⁺);

[0247](3R,5S)-5-(benzylamino-methyl)-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas colorless solid, mp 90° C., MS: 413 (MH⁺);

[0248](3R,5S)-5-[(2-fluoro-benzylamino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas colorless oil, MS: 431 (MH⁺);

[0249](3R,5S)-5-[(benzyl-methyl-amino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas colorless oil, MS: 427 (MH⁺);

[0250](3R,5S)-5-diethylaminomethyl-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas light yellow oil, MS: 379 (MH⁺);

[0251](3R,5S)-5-[(2,4-difluoro-benzylamino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas orange oil, MS: 449 (MH⁺);

[0252](3R,5S)-5-[(2,5-difluoro-benzylamino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas orange oil, MS: 449 (MH⁺);

[0253](3R,5S)-5-{[ethyl-(2-fluoro-benzyl)-amino]-methyl}-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas yellow oil, MS: 459 (MH⁺);

[0254](3R,5S)-5-[(2,3-difluoro-benzylamino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas orange oil, MS: 449 (MH⁺);

[0255](3R,5S)-1-(naphthalene-2-sulfonyl)-5-[(2,3,5-trifluoro-benzylamino)-methyl]-pyrrolidine-3-thiolas colorless oil, MS: 467 (MH⁺);

[0256](3R,5S)-1-(naphthalene-2-sulfonyl)-5-[(2,3,6-trifluoro-benzylamino)-methyl]-pyrrolidine-3-thiolas orange oil, MS: 467 (MH⁺);

[0257](3R,5S)-5-[(methyl-phenethyl-amino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas orange oil, MS: 441 (MH⁺);

[0258](3R,5S)-1-(naphthalene-2-sulfonyl)-5-(phenethylamino-methyl)-pyrrolidine-3-thiolas orange oil, MS: 427 (MH⁺).

[0259](3R,5S)-5-[(dibenzylamino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas white gum, MS: 503 (MH⁺).

[0260] Method B: A slurry of 300 mg (0.73 mmol) (2S,4R)-methanesulfonicacid1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethylester and 109 mg (0.73 mmol) of NaI in 5 ml benzylamine was heated inthe oil bath to 100° C., evaporated in the kugelrohr at 50-70° C./1 Torrand extracted with aqueous saturated NaHCO₃ solution/Et₂O (3×). Theorganic phase was dried over Na₂SO₄, evaporated and the residue wascrystallized from Et₂O/pentane at −20° C. to give 200 mg (65%) of(2S,4R)-benzyl-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylrmethyl]-amine,mp 63-64° C., MS: 421 (MH⁺).

[0261] (Method 2): 100 mg (0.24 mmol) of(2S,4R)-benzyl-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethyl]-aminewas dissolved in 8.5 ml TFA and treated at 0° C. with 0.38 ml (2.38mmol) triethylsilane. The reaction was warmed up over night, heated 1.5h at 80° C. and evaporated, partitioned between water (10 ml)/Et₂O (2xlOml). The water was lyophilized to give 90 mg (91%) of(3R,5S)-5-(benzylamino-methyl)-1-methanesulfonyl-pyrrolidine-3-thioltrifluoro-acetate, MS: 301 (MH⁺).

[0262] In analogy: Methanesulfonic acid(2R,4R)-2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethylester and aniline gave(3R,5R)-1-methanesulfonyl-5-(2-phenyl-amino-ethyl)-pyrrolidine-3-thioltrifluoro-acetate (1:1), mp 122.5-123° C., MS: 301 (MH⁺);

[0263] (2S,4R)-methanesulfonic acid1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethylester with N-benzylmethylamine gave(3R,5S)-5-[(benzyl-methyl-amino)-methyl]-1-methanesulfonyl-pyrrolidine-3-thioltrifluoro-acetate, MS: 315 (MH⁺).

[0264] Method C: A solution of 130 mg (0.257 mmol)(2R,4R)-2-(3-methane-sulfonyloxy-propyl)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid butyl ester, 0.037 ml (0.514 mmol) pyrrole and 38.6 mg (0.257 mmol)NaI in 0.4 ml DMF was treated at 0° C. with 22.4 mg (0.514 mmol) 55% NaHand warmed up over night to room temperature. The reaction wasneutralized with cooled aqueous saturated NH₄Cl and extracted (EtOAc3×). The organic phase was washed with aqueous 10% NaCl, dried (Na₂SO₄)evaporated and purified by flash silica gel column (Hexane/EtOAc 9:1) togive 75 mg (68%) of(2R,4R)-4-(4-methoxy-benzylsulfanyl)-2-(3-pyrrol-1-yl-propyl)-pyrrolidine-1-carboxylicacid butyl ester, MS: 431 (MH⁺).

[0265] (Method 1): A solution of 0.065 g (0.151 mmol)(2R,4R)-4-(4-methoxy-benzylsulfanyl)-2-(3-pyrrol-1-yl-propyl)-pyrrolidine-1-carboxylicacid jbutyl ester was dissolved in 2 ml TFA, cooled to 0 aC and treatedwith 0.24 ml (1.51 mmol) triethylsilane, stirred for 22 h at roomtemperature and treated again with 0.24 ml (1.51 mmol) triethylsilaneafter further 30 h the evaporated residue was purified by flash silicagel column (CH₂Cl₂/EtOAc 99:1) to give 10 mg of(2S,4R)-4-mercapto-2-(3-pyrrol-1-yl-propyl)-pyrrolidine-1-carboxylicacid butyl ester, MS: 311 (MH⁺).

[0266] In analogy:(2R,4R)-2-(3-methanesulfonyloxy-propyl)-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid butyl ester with imidazol gave(2S,4R)-2-(3-imidazol-1-yl-propyl)-4-mercapto-pyrrolidine-1-carboxylicacid butyl ester, MS: 312 (MH⁺);

[0267] (2R,4R)-methanesulfonic acid3-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-propylester with pyrrole gave(3R,5R)-1-methanesulfonyl-5-(3-pyrrol-1-yl-propyl)-pyrrolidine-3-thiol,MS: 289 (MH⁺).

Example 3 Thioether

[0268] A slurry of 300 mg (0.73 mmol) (2S,4R)-methanesulfonic acid1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethylester and 109 mg (0.73 mmol) of NaI in 3 ml DMF at 0° C. was treatedwith 0.35 ml (2.93 mmol) benzylmercaptane and 96 mg (2.2 mmol) 55% NaH.The reaction was warmed up during 2 h to room temperature: and worked upwith aqueous saturated NH₄Cl solution/EtOAc (3×). The organic phase wasdried over Na₂SO₄, evaporated and purified by crystallization (Et₂O) togive 158 mg (49%) of(2S,4R)-2-benzylsulfanylmethyl-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidine,mp 69-71° C., MS: 438 (MH⁺).

[0269] (TFA/triethylsilane for not labile methoxy-benzylsulfanyl, Method2): 100 mg (0.23 mmol) of(2S,4R)-2-benzylsulfanylmethyl-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidinewas dissolved in 8.2 ml TFA and treated at 0° C. with 0.35 ml (2.38mmol) triethylsilane. The reaction was warmed up over night, heated 2.5min at 80° C. and evaporated. Flash silica gel column (CH₂Cl₂/EtOAc99:1) gave 15 mg (21%) of(3R,5S)-5-benzylsulfanylmethyl-1-methanesulfonyl-pyrrolidine-3-thiol, mp101.5-103.5° C., MS: 318 (MH⁺).

Example 4 Amines (via Azide)

[0270] To a solution of 10.12 g (19.4 mmol) methanesulfonic acid(2S,4R)-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethylin 65 ml DMF were added 1.78 g (27.4 mmol, 1.4 eq) NaN₃. The solutionwas stirred at 80° C. overnight, recooled and water was added. Thephases were separated and the inorganic one was extracted with Et₂O, thecombined organic layers were washed with water and brine, dried overNa₂SO₄ and evaporated. Trituration with hexane gave 7.8 g (86%)(2S,4R)-2-azidomethyl-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidineas white solid, mp 143° C., MS: 469 (MH⁺).

[0271] Analogously the following compounds were prepared:

[0272] From methanesulfonic acid(2S,4R)-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-ylmethylester:(2S,4R)-2-azidomethyl-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidineas white foam, MS: 591 (MH⁺).

[0273] From(2S,4R)-2-methanesulfonyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester:(2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidtert-butyl ester as yellow oil, MS: 501 (MH⁺).

[0274] From (2S,4R)-methanesulfonic acid1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethylester:(2S,4R)-2-azidomethyl-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidineas white crystalline, MS: 357 (MH⁺).

[0275] From methanesulfonic acid(2R,4R)-2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethylester:(2S,4R)-2-(2-azido-ethyl)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidineas light yellow foam, MS: 493 (MH⁺).

[0276] From (2R,4R)-methanesulfonic acid2-[i-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-ethylester:(2R,4R)-2-(2-azido-ethyl)-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidineas white foam, MS: 605 (MH⁺).

Example 4.a Methylamine-Optimization

[0277] Staudinger-NH₂ Formation:

[0278] 1.7 g (2.9 mmol)(2S,4R)-2-Azidomethyl-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidinewere treated with 2.3 g (8.8 mmol, 3 eq) of triphenyl phosphine in 12 mlTHF and 0.5 ml H₂O for 2 days at RT. The solution was diluted withEtOAc, extracted with H₂O and aqueous saturated NaHCO₃ solution, washedwith brine, dried over Na₂SO₄ and evaporated. The residue was purifiedby flash chromatography on silica gel with CH₂Cl₂/MeOH 95:5 yielded 1.6g (99%)(2S,4R)—C-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-methylamineas white foam, MS: 565 (MH⁺).

[0279] Analogously the following compounds were prepared:

[0280] From(2S,4R)-2-azidomethyl-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidine:(2S,4R)—C-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methylamineas light yellow solid, mp 88-89° C., MS: 443 (MH⁺).

[0281] From(2R,4R)-2-(2-azido-ethyl)-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidine:(2R,4R)-2-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-ethylamineas white foam MS: 579 (MH⁺).

[0282] Reductive Amination:

[0283] 250 mg (0.56 mmol)(2S,4R)—C-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-methylamineand 58 II (0.5 mmol) o-tolualdehyde in 1 ml MeOH were treated with asolution of 57 mg (0.3 mmol, 0.6 eq) SnCl₂ and 38 mg (0.6 mmol, 1.2 eq)NaBH₃CN in 1 ml MeOH at room temperature and subsequent cleavage of theprotecting group (Method 3) gave(3R,5S)-5-[(2-methyl-benzylamino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas white solid, mp 122° C., MS: 427 (MH⁺).

[0284] Analogously the following compounds were prepared:

[0285] From(2S,4R)—C-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-methylamine

[0286] a) and 2,4-dimethoxybenzaldehyde and subsequent cleavage of theprotecting group (trityl deprotection, Method 3)(3R,5S)-5-[(2,4-dimethoxy-benzylamino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas colorless oil, MS: 473 (MH⁺).

[0287] b) and 4-pyridinecarboxaldehyde and subsequent cleavage of theprotecting group (trityl deprotection, Method 3)(3R,5S)-1-(naphthalene-2-sulfonyl)-5-[[(pyridin-4-ylmethyl)-amino]-methyl]-pyrrolidine-3-thiolas yellow oil, MS: 414 (MH⁺).

[0288] c) and 3-pyridinecarboxaldehyde and subsequent cleavage of theprotecting (Method 3)(3R,5S)-1-(naphthalene-2-sulfonyl)-5-[[(pyridin-3-ylmethyl)-amino]-methyl]-pyrrolidine-3-thiolas colorless oil, MS: 414 (MH⁺).

[0289] d) and 3-fluoro-p-anisaldehyde and subsequent cleavage of theprotecting group (trityl deprotection, Method 3)(3R,5S)-5-[(3-fluoro-4-methoxy-benzylamino)-methyl]-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas colorless oil, MS: 461 (MH⁺).

[0290] e) and benzyloxyacetaldehyde and subsequent cleavage of theprotecting group (trityl deprotection, Method 3)(3R,5S)-5-[(2-benzyloxy-ethylamino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas colorless oil, MS: 457 (MH⁺).

[0291] f) and 2-thiophenecarboxaldehyde and subsequent cleavage of theprotecting group (trityl deprotection, Method 3)(3R,5S)-1-(naphthalene-2-sulfonyl)-5-{[(thiophen-2-ylmethyl)-amino]-methyl}-pyrrolidine-3-thiolas colorless oil, MS: 419 (MH⁺).

[0292] g) and cyclohexanecarboxaldehyde and subsequent cleavage of theprotecting group (trityl deprotection, Method 3)(3R,5S)-5-[(cyclohexylmethyl-amino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas colorless oil, MS: 418 (MH⁺).

[0293] From(2S,4R)—C-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methylamineand isobutylaldehyde and subsequent cleavage of the protecting group(Method 2)(3R,5S)-5-(isobutylamino-methyl)-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas white solid, mp 73° C., MS: 379 (MH⁺).

[0294] From(2R,4R)-2-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-ethylamineand 2,5-difluorobenzaldehyde and subsequent cleavage of the protectinggroup(3R,5R)-5-[2-(2,5-difluoro-benzylamino)-ethyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas colorless oil, MS: 463 (MH⁺).

[0295] From(2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidtert-butyl ester was prepared via(2S,4R)-2-aminomethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidtert-butyl ester [as light brown foam, MS: 475 (MH⁺)] and furtherreaction with 2,5-difluoro benzaldehyde analogously to reductiveamination gave(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester as colorless oil MS: 601 (MH⁺) which was treatedaccording to trityl cleavage (method 5) to give(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid tert-butyl ester as colorless liquid MS: 359 (MH⁺).

Example 4.b N-Pyrrolidine: Carbamates

[0296] (2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl with TFA in CH₂Cl₂ (following the general method for aselective BOC-deprotection) gave(2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine as light yellow oil,MS: 501 (MH⁺).

[0297] (2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine and benzylchloroformate/N-ethyldiisopropylamine in CH₂Cl₂ (see cabamate synthesis,Method A)—followed by Staudinger reduction gave(2S,4R)-2-aminomethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidbenzyl ester as white foam, MS: 509 (MH⁺).

[0298] (2S,4R)-2-aminomethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid benzyl ester and 2,5-difluorobenzaldehyde and subsequent cleavageof the trityl protecting group analogously to reductive amination anddeprotection gave(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid benzyl ester as colorless oil, MS: 393 (MH⁺).

[0299] In a similar manner, the following compounds were prepared from

[0300] (2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine, but replacingbenzyl chloroformate with 4-fluorophenyl chloroformate, isopropylchloroformate, chloroformic acid 2-naphthyl ester, 1,4-benzodioxan-5-ylchloroformate[Eitel & Hammann, I. Benzodioxan-N-methylcarbamates usefulas insecticides or acaricides. S. African, 14 pp. ZA 6800512 680627.]and in situ prepared chloroformates from 1-naphthalene ethanol and2-naphthalene ethanol, respectively, (by treatment with trichloromethylchloroformate, quinoline in CH₂Cl₂, see Carbamate, Method B).

[0301](2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid 4-fluoro-phenyl ester as colorless oil, MS: 397 (MH⁺).

[0302](2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid isopropyl ester as colorless oil, MS: 345 (MH⁺).

[0303](2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid naphthalen-2-yl ester as colorless oil, MS: 429 (MH⁺).

[0304](2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo[1,4]dioxin-5-yl ester as colorless oil, MS: 437(MH⁺).

[0305](2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid butyl ester as colorless oil, MS: 359 (MH⁺).

[0306](2S,4R)-2-[(2,5-Difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid 2-naphthalen-1-yl-ethyl ester as colorless oil, MS: 457 (MH⁺).

[0307](2S,4R)-2-[(2,5-Difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid 2-naphthalen-2-yl-ethyl ester ester as colorless oil, MS: 457(MH⁺).

Example 4.c N-Pyrrolidine: Sulfamides

[0308] To 4.2 ml (48.65 mmol, 1.2 eq) oxalyl chloride in 100 ml CH₂Cl₂were added 6.5 ml (89.19 mmol, 2.2 eq) DMSO in 20 ml CH₂Cl₂ at −65° C.,followed after 10 min by 14.33 g (40.54 mmol, 1.0 eq)(2S,4R)-2-hydroxymethyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester in 60 ml CH₂Cl₂ over a period of 20 min. Thesolution was stirred at −68° C. for 1.5 h before 28 ml (162.16 mmol, 4eq) iPr₂NEt were added, and the reaction mixture was warmed to roomtemperature. The solution was extracted with 1M KHSO₄, the combinedinorganic phases were extracted with CH₂Cl₂ and the organic phase driedover Na₂SO₄ and evaporated, yielding 14.18 g (99%)(2S,4R)-2-formyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester. The crude product was subjected to the followingreaction without further purification.

[0309] To 14.18 g (40.54 mmol)(2S,4R)-2-formyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester in 250 ml CH₂Cl₂ were added 4.88 g MgSO₄, followedby 4.8 ml (40.9 mmol, 1.0 eq) t2,5-difluoro-benzylamine. The suspensionwas stirred at RT overnight, filtered and evaporated. The crude yellowoil was purified by flash chromatography with EtOAc/hexane 1:3 yielding17.31 g(2S,4R)-2-[(2,5-difluoro-benzylimino)-methyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester (90%, 2 steps) as yellow oil.

[0310] To 17.31 g (36.32 mmol)(2S,4R)-2-[(2,5-difluoro-benzylimino)-methyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester in 120 ml MeOH were added 1.64 g (43.58 mmol, 1.2eq) NaBH₄ slowly at 40° C. The solution was stirred at that temperaturefor additional 90 min, water was added carefully and the solution wasconcentrated. The residue was redissolved in EtOAc and washed withNaHCO₃ and brine, dried over Na₂SO₄ and evaporated. Flash chromatographywith EtOAc/hexane 1:1 yielded 11.57 g (67%)(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester as yellow oil, MS: 479 (MH⁺).

[0311] To 3.19 g (6.67 mmol, 1 eq)(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester in 10 ml CH₂Cl₂ were added 1.35 ml (8.0 mmol, 1.2eq) EtNiPr₂, followed by 2.07 g (8.0 mmol, 1.2 eq) 9-fluorenylmethylchloroformate and a catalytic amount of DMAP at 0° C. The solution wasstirred at room temperature overnight, 5% NaHCO₃ solution was added (pH9), the layers were separated and the inorganic one was extracted withCH₂Cl₂. The combined organic layers were washed with 1M KHSO₄ and brine,dried over Na₂SO₄ and evaporated. The crude product was purified byflash chromatography with EtOAc/hexane 1:3 as eluent yielding 3.81 g(82%)(2S,4R)-2-{[(2,5-difluoro-benzyl)-(9H-fluoren-9-ylmethoxy-carbonyl)-amino]-methyl}-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester as white foam, which was subjected to the nextreaction directly.

[0312] To 2.27 g (3.24 mmol)(2S,4R)-2-{[(2,5-Difluoro-benzyl)-(9H-fluoren-9-ylmethoxycarbonyl)-amino]-methyl}-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester in 10 ml CH₂Cl₂ were added 3.4 ml TFA at 0° C.,and the solution was stirred at room temperature for 2 h. The solventwas evaporated and the crude oil redissolved and evaporated successivelywith toluene, hexane and Et₂O yielding 2.46 g(2S,4R)-(2,5-difluoro-benzyl)-[4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethyl]-carbamicacid 9H-fluoren-9-ylmethyl ester as TFA salt as brown oil.

[0313] To 300 mg (0.42 mmol)(2S,4R)-2,5-difluoro-benzyl)-[4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethyl]-carbamicacid 9H-fluoren-9-ylmethyl ester as TFA salt in 5 ml CH₂Cl₂ were added290 tll (1.68 mmol, 4 eq) EtNiPr₂, followed by 121 mg (0.59 mmol, 1.4eq) benzylsulfamoyl chloride at 0° C. The solution was stirred at roomtemperature for 48 h, 1M KHSO₄ was added, the layers were separated andthe inorganic one was extracted with CH₂Cl₂. The combined organic layerswere washed with 1M KHSO₄ and brine, dried over Na₂SO₄ and evaporated.The crude product was dissolved in 4.2 ml Et₂NH:THF (1:1) at 0° C. andstirred 5 h at room temperature. The solvent was evaporated, the residueredissolved and evaporated twice with hexane and dried in vacuum. Thebrown oil was dissolved in 4 ml TFA and 0.7 ml (4.2 mmol) Et₃SiH andstirred at 80° C. for 2 h. The solution was concentrated, redissolved inEtOAc and NaHCO₃ solution, the layers were separated and the inorganicone was extracted with EtOAc, the combined organic ones were washed withbrine, dried over Na₂SO₄ and evaporated. The crude product was purifiedpurified by flash chromatography with CH₂Cl₂/MeOH 95:5 yielding 16.8 mg(10%, 3 steps)(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-sulfonicacid benzylamide as white oil, MS: 427 (MH⁺).

[0314] In a similar manner, but replacing benzylsulfamoyl chloride withcyclopropyl-sulfamoyl chloride and n-butylsulfamoyl chloride thefollowing compounds were prepared:

[0315](2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-sulfonicacid cyclopropylamide as colorless oil, MS: 377 (MH⁺).

[0316](2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-sulfonicacid butylamide as colorless oil, MS: 393 (MH⁺).

Example 4.c N-Pyrrolidines: Ureas

[0317] From(2S,4R)-2-Azidomethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidtert-butyl ester was prepared(2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine according toBOC-cleavage example general method B (variation 0° C., 2 h).

[0318] 280 mg (0.7 mmol)(2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine were treated with 87μM (0.77 mol, 1.1 eq) butyl isocyanate in 5 ml THF at 0° C., and thesolution was stirred at RT for 45 min. The solvent was evaporated, andthe residue was purified by flash chromatography yielding 278 mg (80%)(2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidbutylamide as white foam.

[0319] 275 mg (0.55 mmol)(2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidbutylamide in 8 ml ethanol was treated with 83 mg (2.2 mmol) NaBH₄ at80° C. for 18 h. Additional 175 mg (4.6 mmol) NaBH₄ were added inportions, and the reaction was stirred at 80° C. until no startingmaterial could be detected. The solution was poured into a saturatedNH₄Cl solution, and was extracted with EtOAc, the organic phase waswashed with brine, dried over Na₂SO₄ and evaporated. Columnchromatography yielded 213 mg (82%)(2S,4R)-2-aminomethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidbutylamide as white foam, which was directly subjected to the followingreactions according to reductive amination with2,5-difluoro-benzaldehyde (example 4a) and subsequent trityl cleavage(method 3) yielding(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid butylamide as colorless oil, MS:358 (MH⁺).

[0320] Analogously, the following compounds were prepared from(2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine and 2-fluorophenylisocyanate or benzylisocyanate and 2,5-difluorobenzaldehyde.

[0321](2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid (2-fluoro-phenyl)-amide as white solid, mp 126° C., MS: 396 (MH⁺).

[0322](2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid benzylamide as colorless oil, MS: 392 (MH⁺).

Example 5 Second Substituent on Methylamine (Y=N)

[0323] 6.94 g (14.5 mmol)(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester were dissolved in 170 ml acetonitrile and treatedwith 3 ml (20.3 mmol, 1.4 eq) t-butyl bromoacetate and 18.6 g (134.9mmol, 9.3 mmol) K₂CO₃ at RT for 2d. The solid was removed by filtration,and the organic phase was washed with water and brine, dried over Na₂SO₄and evaporated, yielding 9.02 g (quant)(2S,4R)-2-[[tert-butoxycarbonylmethyl-(2,5-difluoro-benzyl)-amino]-methyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester as orange oil, MS: 593 (MH⁺).

[0324] 397 mg (0.67 mmol)(2S,4R)-2-[[tert-butoxycarbonylmethyl-(2,5-difluoro-benzyl)-amino]-methyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester were treated with 4.2 ml 1N HCl in EtOAc at RT.The reaction mixture was concentrated and tituration with ether yielded250 mg (76%)(2S,4R)-[(2,5-difluoro-benzyl)-[4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethyl]-amino]-aceticacid tert-butyl ester as light brown solid, which was transformed to(2S,4R)-2-[[tert-butoxycarbonylmethyl-(2,5-difluoro-benzyl)-amino]-methyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid butyl ester according to example 4b by treatment with butylchloroformate.

[0325] 250 mg (0.42 mmol)(2S,4R)-2-[[tert-butoxycarbonylmethyl-(2,5-difluoro-benzyl)-amino]-methyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid butyl ester were treated with 670 μl (4.2 mmol, 10 eq) triethylsilane in 7.5 ml TFA at 80° C. for 1.5 h. The solvent was evaporated andthe residue was redissolved in toluene and evaporated. The crudematerial was purified by flash chromatography yielding 85 mg (49%)(2S,4R)-2-[[carboxymethyl-(2,5-difluoro-benzyl)-amino]-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid butyl ester as light brown oil, MS: 417 (MH⁺).

[0326] Analogously,(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester was treated with 2,5-difluoro-benzylbromide togive(2S,4R)-2-{[bis-(2,5-difluoro-benzyl)-amino]-methyl}-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester which was treated with TFA according to generalmethod B (variation 0° C. to RT) to give(2S,4R)-bis-(2,5-difluoro-benzyl)-(4-tritylsulfanyl-pyrrolidin-2-ylmethyl)-amineyellow oil, MS: 627 (MH⁺).

[0327] Using the procedures described for the reactions in 4a and 4c thefollowing compounds were prepared from(2S,4R)-bis-(2,5-difluoro-benzyl)-(4-tritylsulfanyl-pyrrolidin-2-ylmethyl)-amineand 2-naphthalene sulfonylchloride, N-butyl chloroformate, N-benzylchloroformate, p-methoxyphenyl chloroformate, isopropyl chloroformate:

[0328](2S,4R)-5-[[Bis-(2,5-difluoro-benzyl)-amino]-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas colorless oil, MS: 575 (MH⁺).

[0329](2S,4R)₂-[[Bis-(2,5-difluoro-benzyl)-amino]-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid butyl ester as colorless oil, MS: 485 (MH⁺).

[0330](2S,4R)-2-[[Bis-(2,5-difluoro-benzyl)-amino]-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid benzyl ester as colorless oil, MS: 519 (MH⁺).

[0331](2S,4R)-2-[[Bis-(2,5-difluoro-benzyl)-amino]-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid 4-methoxy-phenyl ester as colorless oil, MS: 535 (MH⁺).

[0332](2S,4R)-2-[[Bis-(2,5-difluoro-benzyl)-amino]-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid isopropyl ester as colorless oil, MS: 471 (MH⁺).

[0333](2S,4R)-2-[[benzyloxycarbonyl-(2,5-difluoro-benzyl)-amino]-methyl]-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester was treated according to trityl cleavage (method5) to give(2S,4R)-2-[[benzyldxycarbonyl-(2,5-difluoro-benzyl)-amino]-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid tert-butyl ester as colorless oil, MS: 493 (MH⁺).

Example 6 Methylamine: Amides and Sulfonamides

[0334] 11 g (83.9 mmol) L-Hydroxyproline were dissolved in 110 mlhexamethyldisilazane and heated to 120° C. overnight, cooled to roomtemperature and evaporated. The oily residue was dissolved in 110 mlTHF, 16.5 ml (79.7 mmol, 0.95 eq) N-ethyl-morpholine was added, followedby 18.25 g (79.7 mmol, 0.95 eq) 2-naphthalenesulfonyl chloride in 130 mlTHF over a period of 60 min. The solution was stirred at RT for 50 h, 15ml ethanol were added and the solution was stirred for 15 min. At thattime 400 ml of Et₂O and 250 ml of aqueous saturated NaHCO₃ solution wereadded and the phases were separated. The aqueous layer was acidified andextracted with EtOAc, the combined organic layers were washed withbrine, dried over MgSO₄ and concentrated. 17.39 g (65%)(2S,4R)-4-hydroxy-1-(naphthalene-2-sulfonyl)₇ pyrrolidine-2-carboxylicacid isolated as yellow solid, mp 140° C., MS: 321 (MH⁺).

[0335] 38.97 g (121.4 mmol)(2S,4R)-4-hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid were dissolved in 97 ml MeOH and 64.5 ml 1.75 M (112.8 mmol) HCl inMeOH were added and the solution heated to reflux for 3 h andconcentrated. Trituration with hexane yielded 41.4 g (quant.)(2S,4R)-4-hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid methyl ester as brown solid, MS: 335 (MH⁺).

[0336] 29 ml (194 mmol, 1.6 eq) DBU were added to a suspension of 41.4 g(121.4 mmol)(2S,4R)-4-Hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid methyl ester in 150 ml acetonitrile at 0° C. To the resultingsolution 29.25 g (194 mmol, 1.6 eq) TBDMSCl were added in portions andthe reaction was stirred at RT overnight. After concentrating the crudeoil was purified by column chromatography with EtOAc/hexane 1:2 onsilica gel to give 49.2 g (90%)(2S,4R)-4-(tert-butyl-dimethyl-silanyloxy)-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid methyl ester.

[0337] 3.4 g (148 mmol, 95%, 2.7 eq) LiBH₄ were added in small portionsto a solution of 24.5 g (54.6 mmol)(2S,4R)-4-(tert-Butyl-dimethyl-silanyloxy)-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid methyl ester in 11 THF at 0° C. The solution was stirred overnight,further 1.8 g (78 mmol, 95%, 1.4 eq) LiBH₄ were added and stirred foradditional 48 h, before 10 ml acetic acid in 30 ml THF were added undercooling. 650 ml 5% NaHCO₃ solution were added slowly, the phases wereseparated, and the inorganic one was extracted with EtOAc. The combinedorganic ones were washed with brine, dried over Na₂SO₄ and evaporatedyielding 22.3 g of a light yellow oil. An analytical sample was purifiedon silica gel with EtOAc/hexane 1:2 as solvent,(2S,4R)-[4-(tert-butyl-dimethyl-silanyloxy)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanolas white powder, MS: 422 (MH⁺).

[0338] 24.34 g (57.73 mmol)(2S,4R)-[4-(tert-butyl-dimethyl-silanyloxy)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanolin 380 ml toluene were treated with 17.57 g (67 mmol, 1.16 eq)triphenylphosphine, 10.02 g (68.12 mmol, 1.18 eq) phthalimide. 13.8 ml(88.9 mmol, 1.5 eq) DEAD in 65 ml toluene were added to the solutionover a period of 2.5 h, keeping the temperature below 3° C. The mixturewas stirred at room temperature for 48 h, and recooled to 3° C. forfurther addition of 8.79 g (33.5 mmol, 0.58 eq) triphenyl-phosphine,5.01 g (34 mmol, 0.59 eq) phthalimide and 6.9 ml (44.5 mmol, 0.75 eq)DEAD in 35 ml toluene. After stirring at 80° C. for 4 h and at roomtemperature for 3d, additional 8.79 g (33.5 mmol, 0.58 eq) triphenylphosphine, 5.01 g (34 mmol, 0.59 eq) phthalimide and 6.9 ml (44.5 mmol,0.75 eq) DEAD in 35 ml toluene were added, and the reaction heated to80° C. for 3 h, recooled and diluted with EtOAc, extracted with 2M NaOH,aqueous saturated NaHCO₃, brine, dried over Na₂SO₄ and evaporated. Thecrude product was purified by column chromatography on silica gelyielding 15.6 g (50%)(2S,4R)-2-[4-(tert-butyl-dimethyl-silanyloxy)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-isoindole-1,3-dioneand 6.0 g (25%) recovered starting material.

[0339] 14.5 g (26.3 mmol)(2S,4R)-2-[4-(tert-butyl-dimethyl-silanyloxy)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-isoindole-1,3-dionein 145 ml THF were treated with 10.3 g (31.7 mmol, 1.2 eq) TBAF 3H₂O atRT for 1.5 h, the solvent was evaporated and the crude product purifiedby column chromatography on silica gel with a gradient EtOAc/hexane 4:1,EtOAc/CH₂Cl₂ 1:1, CH₂Cl₂/MeOH,9:1 yielding 5.5 g (45%)(2S,4R)-2-[4-hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-isoindole-1,3-dioneas white crystalline, MS: 437 (MH⁺).

[0340] 3.0 ml (21.7 mmol, 1.2 eq) triethylamine and 6.05 g (22.6 mmol,1.2 eq) triphenylphosphine were added to a solution of 1.42 ml (21.7mmol, 1.25 eq) methanesulfonic acid in 60 ml toluene, successivelyfollowed by a solution of 7.9 g (18.1 mmol)(2S,4R)-2-[4-hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-isoindole-1,3-dionein 80 ml toluene/THF (5/3) and 5.06 ml (23.6 mmol, 1.3 eq) DIAD. Thesuspension was heated to 80° C. for 6 h and stirred at room temperatureovernight. After diluting the mixture with EtOAc and water, the phaseswere separated, and the inorganic one was extracted with EtOAc andCH₂Cl₂, the combined organic phases were washed with 1M KHSO₄ and brine,dried over Na₂SO₄ and evaporated. Column chromatography with a gradientof CH₂Cl₂: EtOAc 4:1 to 1:1 yielded 8.3 g (90%) of(3R,5S)-methanesulfonic acid5-(1,3-dioxo-1,3-dihydro-isoindol-2-ylmethyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-ylester as white crystals.

[0341] To 8.3 g (16.1 mmol) (3R,5S)-methanesulfonic acid5-(1,3-dioxo-1,3-dihydro-isoindol-2-ylmethyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-ylester in 210 ml DMF were added 2.82 g (24.2 mmol, 1.5 eq) potassiumthioacetate and heated to 100° C. for 2.5 h. The mixture wasconcentrated under vacuum and the residue was redissolved in EtOAc andwater, the layers were separated and the inorganic one was extractedwith EtOAc (3×). The combined organic phases were extracted withsaturated NaHCO₃ solution and brine, dried over Na₂SO₄ and evaporated.Purification with column chromatography on silica gel with EtOAc/hexane1:1 as eluent yielded 6.8 g (85%) Thioacetic acid(2S,4R)-5-(1,3-dioxo-1,3-dihydro-isoindol-2-ylmethyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-ylas off white crystalline, mp 159° C., MS: 495 (MH⁺).

[0342] 6.35 g (12.85 mmol) Thioacetic acid(2S,4R)-5-(1,3-dioxo-1,3-dihydro-isoindol-2-ylmethyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-ylester treated with 320 ml 33% methylamine in ethanol (8.03 M, 2.57 mol)at room temperature for 2 days. The solvent was evaporated and theresidue was purified on silica gel by column chromatography withCH₂Cl₂/MeOH/NH₄OH 90:10:1 yielding 2.26 g (55%) ofC-[(2S,4R)-4-[(3R,5S)-5-aminomethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yldisulfanyl]-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methylamineas off white foam, MS: 643 (MH⁺).

[0343] To a suspension of 127 mg (0.68 mmol, 1.05 eq)mono-methylterephthalate in 11 ml CH₂Cl₂ were added 77 μl (0.68 mmol,1.05 eq) 4-methyl morpholine, 222 mg (0.75 mmol, 1.2 Eq) TPTU and 200 mg(0.31 mmol)C-[(2S,4R)-4-[(3R,5S)-5-aminomethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yldisulfanyl]-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methylamine.The solution was stirred at room temperature overnight, evaporated andthe residue was purified on silica gel with a gradient of EtOAc/hexane2:1 to 4:1 yielding 248 mg (82%)N-[(2S,4R)-4-[(5S,3R)-5-[(4-methoxycarbonyl-benzoylamino)-methyl]-1-(naphthalene-1-sulfonyl)-pyrrolidin-3-yldisulfanyl]-1-(naphthalene-1-sulfonyl)-pyrrolidin-2-ylmethyl]-terephthalamicacid methyl ester as white foam, which was directly subjected to thenext reaction.

[0344] 238 mg (0.25 mmol) ofN-[(2S,4R)-4-[(5S,3R)-5-[(4-methoxycarbonyl-benzoylamino)-methyl]-1-(naphthalene-1-sulfonyl)-pyrrolidin-3-yldisulfanyl]-1-(naphthalene-1-sulfonyl)-pyrrolidin-2-ylmethyl]-terephthalamicacid methyl ester were suspended in 7 ml 2,2,2-trifluoro ethanol and 38μl H₂O and cooled to 0° C. 87 μl (0.3 mmol) tri-n-butylphosphine wereadded. The mixture was diluted with 1 ml CH₂Cl₂ after 1 h at 0° C., andstirring was continued for another 1 h. Evaporation under vacuum andpurification on silica gel with EtOAc/hexane 1:1 gave 198 mg (83%)(2S,4R)-N-[4-Mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-terephthalamicacid methyl ester as white solid, MS: 485 (MH⁺).

[0345] In a similar manner, but replacing mono-methylterephthalate withcyclohexane carbonic acid, BOC-glycine, BOC-L-tyrosine, BOC-L-leucineand 4-(2,4-dioxo-1,4-dihydro-2H-quinazolin-3-yl)-butyric acid [Puhl etal. PCT Int. Appl. WO 9856770] and successive cleavage of the disulfidebond (analogously to the example described above) the followingcompounds were prepared:

[0346] (2S,4R)-cyclohexanecarboxylic acid[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-amide aswhite foam, MS: 433 (MH⁺);

[0347](2S,4R)-[[[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-carbamoyl]-methyl]-carbamicacid tert-butyl ester as white foam, MS: 480 (MH⁺);

[0348](S)-[2-(4-hydroxy-phenyl)-1-[[(2S,4R)-4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-carbamoyl]-ethyl]-carbamicacid tert-butyl ester as white foam, MS: 586 (MH⁺);

[0349](S)-[1-[[(2S,4R)-4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-carbamoyl]-3-methyl-butyl]-carbamicacid tert-butyl ester as beige foam, MS: 536 (MH⁺);

[0350](2S,4R)-4-(2,4-dioxo-1,4-dihydro-2H-quinazolin-3-yl)-N-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-butyramideas white crystalline, MS: 553 (MH⁺).

[0351] A degassed solution of 102 mg (0.21 mmol)(2S,4R)-N-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-terephthalamicacid methyl ester in 12.6 ml THF was treated with 12.6 ml 0.1 M aqueousLiOH (1.26 mmol, 6 eq) at 0° C. and was stirred at room temperature for1.5 h. 1 M KHSO₄ solution was added (pH 2), the layers were separatedand the inorganic one was extracted with EtOAc. The combined organicones were washed with water and brine, dried over Na₂SO₄ and evaporated,yielding(2S,4R)-N-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-terephthalamicacid as white foam, MS: 471 (MH⁺).

[0352] Reaction with Sulfonyl- or Acid-Chlorides:

[0353] To 100 mg (0.16 mmol)C-[(2S,4R)-4-[(3R,5S)-5-aminomethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yldisulfanyl]1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methylaminein 8 ml CH₂Cl₂ were added 58 mg (0.47 mmol, 2.9 eq) DMAP and 80 mg (0.47mmol, 2.9 eq) toluene sulfonylchloride. The solution was stirred at roomtemperature for 2 h and was evaporated. The crude oil was purified onsilica gel with CH₂Cl₂: EtOAc 9:1 yielding 129 mg (87%)4-methyl-N-[(2S,4R)-4-[(3R,5S)-5-[(4-methyl-benzenesulfonylamino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yldisulfanyl]-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-benzenesulfonamideas white crystalls.

[0354] Cleavage of the disulfide bond analogously to the exampledescribed above yielded 120 mg (94%)(2S,4R)-N-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-4-methyl-benzenesulfonamideas white crystalline, mp 175° C., MS: 477 (MH⁺).

[0355] In a similar manner, but replacing toluene sulfonylchloride with2-naphthalene sulfonylchloride, methyl sulfonylchloride, acetylchloride, benzoyl chloride and successive cleavage of the disulfide bond(analogously to example described above) the following compounds wereprepared:

[0356] Naphthalene-2-sulfonic acid(2S,4R)-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-amideas white crystalline, mp 156° C., MS: 513 (MH⁺);

[0357](2S,4R)-N-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-methanesulfonamideas beige crystalline, mp 136° C., MS: 401 (MH⁺);

[0358](2S,4R)-N-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-acetamideas white crystalline, mp 145° C., MS: 365 (MH⁺);

[0359](2S,4R)-N-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-benzamideas white crystalline, MS: 427 (MH⁺).

[0360] In analogy Z-L-hydroxyproline benzylester hydrochloride gave(2S,4R)-4-mercapto-2-[(naphthalene-2-sulfonylamino)-methyl]-pyrrolidine-1-carboxylicacid benzyl ester as white solid, MS: 457 (MH⁺);

Example 7 Heteroaromates

[0361] (The heteroaromatic compounds were prepared according toCottrell, Ian F.; Hands, David; Houghton, Peter G.; Humphrey, Guy R., J.Heterocyclic Chem., 28, 301-304 (1991))

[0362] To a suspension of 281 mg (2.0 mmol, 4 eq.) potassium carbonatein 2 ml DMSO were added 300 mg (0.51 mmol)(2S,4R)-2-azidomethyl-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidineand 72 tll (0.7 mmol, 1.38 eq) acetyl acetone. The reaction mixture wasstirred at 40° C. for 3 d, diluted with water and extracted with Et₂O,the layers were separated and the inorganic one was extracted withEtOAc, the combined organic layers were washed with brine, dried overNa₂SO₄ and evaporated. The residue was purified by column chromatographyon silica gel with EtOAc/hexane 1:1 yielding 249 mg (73%)(2S,4R)-1-{5-methyl-1-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-ylmethyl]-1H-[1,2,3]triazol-4-yl}-ethanoneas white foam, MS: 673 (MH⁺). 150 mg (0.2 mmol)(2S,4R)-1-{5-methyl-1-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-ylmethyl]-1H-[1,2,3]triazol-4-yl}-ethanonewere dissolved in 6.5 ml acetonitrile and 3 ml TFA and were treated with0.5 ml triethylsilane at 40° C. for 4 h. The reaction mixture was addedto a aqueous saturated NaHCO₃ solution carefully, extracted, and theorganic layer was washed with water and brine, dried over Na₂SO₄ andevaporated. Purification by column chromatography on silica gel withEtOAc/hexane 1:1 gave 63 mg (66%)(2S,4R)-1-[1-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-5-methyl-1H-[1,2,3]triazol-4-yl]-ethanoneas white solid, mp 145° C., MS: 431 (MH⁺).

[0363] In a similar manner the following compounds were prepared:

[0364] From(2S,4R)-2-azidomethyl-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidine

[0365] b) and ethyl acetoacetate(2S,4R)-1-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-5-methyl-1H-[1,2,3]triazole-4-carboxylicacid ethyl ester as white solid, mp 121° C., MS: 581 (MH⁺);

[0366] c) and cyano acetamide(2S,4R)-5-amino-1-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-1H-[1,2,3]triazole-4-carboxylicacid amide as off-white solid, mp 190° C., MS: 553 (MH⁺);

[0367] From(2S,4R)-2-azidomethyl-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidine

[0368] d) and acetyl acetone(2S,4R)—l{1-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethyl]-5-methyl-1H-[1,2,3]triazol-4-yl}-ethanoneas white foam, MS: 439 (MH⁺);

[0369] e) and ethyl acetoacetate(2S,4R)-1-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethyl]-5-methyl-1H-[1,2,3]triazole-4-carboxylicacid ethyl ester as white foam, MS: 469 (MH⁺);

[0370] f) and phenyl acetone(2S,4R)-1-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethyl]-5-methyl-4-phenyl-1H-[1,2,3]triazoleas white foam, MS: 473 (MH⁺).

[0371] g) and cyano acetamide(2S,4R)-5-amino-1-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethyl]-1H-[1,2,3]triazole-4-carboxylicacid amide as white foam, MS: 441 (MH⁺);

[0372] h) and benzyl cyanide(2S,4R)-3-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethyl]-5-phenyl-3H-[1,2,3]triazol-4-ylamineas white foam, MS: 473 (MH⁺);

[0373] From(2S,4R)-2-(2-azido-ethyl)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidine

[0374] i) and acetyl acetone(2S,4R)-1-[1-[2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethyl]-5-methyl-1H-[1,2,3]triazol-4-yl]-ethanoneas white foam, MS: 575 (MH⁺);

[0375] j) and ethyl acetoacetate(2S,4R)-1-[2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethyl]-5-methyl-1H-[1,2,3]triazole-4-carboxylicacid ethyl ester as white foam, MS: 605 (MH⁺);

[0376] k) and phenyl acetone(2S,4R)-1-[2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethyl]-5-methyl-4-phenyl-1H-[1,2,3]triazoleas white foam, MS: 609 (MH⁺);

[0377] Cleavage of the protecting group analogously (for Trityl: seeexample a) above, for methoxy-benzylsulfanyl: Method 2) to yield:

[0378] a)(2S,4R)-1-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-5-methyl-1H-[1,2,3]triazole-4-carboxylicacid ethyl ester as white solid, mp 95° C., MS: 459 (M−H⁺);

[0379] b)(3R,5S)-5-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas light yellow solid, mp 146° C., MS: 465 (MH⁺);

[0380] c)(3R,5S)-5-(5-amino-4-phenyl-[1,2,3]triazol-1-ylmethyl)-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas white solid, mp 70° C., MS: 466 (MH⁺);

[0381] d)(2S,4R)-1-(4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethyl)-5-methyl-1H-[1,2,3]triazole-4-carboxylicacid ethyl ester as white solid, mp 123° C., MS:469(MH⁺);

[0382] e)(3R,5S)-1-methanesulfonyl-5-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-3-thiolas white solid, mp 150° C., MS:473(MH⁺);

[0383] f)(2S,4R)-5-amino-1-(4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethyl)-1H-[1,2,3]triazole-4-carboxylicacid amide as white solid, mp 189° C., MS: 321(MH⁺);

[0384] g)(3R,5S)-5-(5-amino-4-phenyl-[1,2,3]triazol-1-ylmethyl)-1-methanesulfonyl-pyrrolidine-3-thiolas white foam, MS: 354(MH⁺);

[0385] h)(2S,4R)-1-[1-[2-(4-mercapto-1-methanesulfonyl-pyrrolidin-2-yl)-ethyl]-5-methyl-l1H-[1,2,3]triazol-4-yl]-ethanoneas colorless oil, MS: 317 (M-CH₃ ⁺);

[0386] i)(2S,4R)-1-[2-(4-mercapto-1-methanesulfonyl-pyrrolidin-2-yl)-ethyl]-5-methyl-1H-[1,2,3]triazole-4-carboxylicacid ethyl ester as colorless oil, MS: 363 (MH⁺);

[0387] j)(3R,5S)-1-methanesulfonyl-5-[2-(5-methyl-4-phenyl-[1,2,3]triazol-1-yl)-ethyl]-pyrrolidine-3-thiolas colorless oil, MS: 366 (MH⁺);

[0388] Saponification of the ethyl ester analogously to (see above:General method for hydrolysis of an ester) yielded:

[0389](2S,4R)-1-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-5-methyl-1H-[1,2,3]triazole-4-carboxylicacid as white solid, mp 218° C., MS: 431(M−H⁻).

[0390] In a similar manner, but without isolation of intermediates thefollowing compounds were prepared:

[0391](2S,4R)-2-azidomethyl-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidineand methyl benzyl ketone and removal of the PMB protecting group (Method2)(2S,4R)-1-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-5-methyl-1H-[1,2,3]triazole-4-carboxylicacid as white solid, mp 218° C., MS: 431 (M−H⁻);

[0392] From(2S,4R)-2-azidomethyl-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidineand benzyl cyanide and and removal of the.PMB protecting group (Method2)(2S,4R)-5-amino-1-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-1H-[1,2,3]triazole-4-carboxylicacid amide as white solid, mp 130° C., MS: 433 (MH⁺);

[0393] From(2R,4R)-2-(2-azido-ethyl)-1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidineand phenyl acetone and removal of the protecting group(3R,5R)-5-[2-(5-methyl-4-phenyl-[1,2,3]triazol-1-yl)-ethyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas light yellow foam, MS: 479 (MH⁺).

Example 8 N-Pyrrolidine-Optimization, Heteroaromates

[0394] In analogy to above Example 7:(2S,4R)-2-azidomethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidtert-butyl ester and phenyl acetone gave(2S,4R)-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester as yellow crystals, MS: 616 (MH⁺).

[0395](2S,4R)-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester gave by treatment with TFA in methylene chloride(following the general method for a selective BOC-deprotection)(2S,4R)-5-methyl-4-phenyl-1-(4-tritylsulfanyl-pyrrolidin-2-ylmethyl)-1H-[1,2,3]triazoleas yellow foam, MS: 517 (MH⁺);

[0396] (2S,4R)-5-methyl-4-phenyl-1(4-tritylsulfanyl-pyrrolidin-2-ylmethyl)-1H-[1,2,3]triazole and benzylchloroformate, N-ethyldiisopropylamine in CH₂Cl₂ (see carbamatesynthesis, Method A) followed by the removal of the trityl-protectinggroup (see Method 3) gave(2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid benzyl ester as white foam, MS: 409(MH⁺).

[0397] In a similar manner but replacing benzyl chloroformate withisopropyl chloroformate, phenyl chloroformate, chloroformic acid2-naphtyl ester, 1,4-benzodioxan-5-yl chloroformate [Eitel, A. &Hammann, I. S. African, ZA 6800512 680627] and butyl chloroformate thefollowing compounds were prepared:

[0398](2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid isopropyl ester as colorless oil, MS: 361 (MH⁺);

[0399](2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-(1,2,3)triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid phenyl ester as white foam, MS: 395 (MH⁺);

[0400](2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid naphthalen-2-yl ester as colorless oil, MS: 445 (MH⁺);

[0401](2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo[1,4]dioxin-5-yl ester as colorless oil, MS:453(MH⁺);

[0402](2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid butyl ester as colorless oil, MS: 375(MH⁺).

Example 9 Ether, Phenolethers

[0403] 0.37 ml (2.25 mmol) DEAD was added at −15° C. to 590 mg (2.25mmol) triphenylphosphine in 3 ml THF. Then a solution of 497 mg (1.5mmol)(2S,4R)-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-methanoland 146 mg (1.5 mmol) phenol in 2 ml THF was added. The reaction wasstirred at 0° C. over night, heated to reflux and evaporated underreduced pressure. Flash silica gel column (hexane/EtOAc 4:1) gave 240 mg(39%) of(2S,4R)-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-2-phenoxymethyl-pyrrolidine,mp 92-94° C., MS: 408 (MH⁺).

[0404] (Method 2): A solution of 102 mg (0.25 mmol)(2S,4R)-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-2-phenoxymethyl-pyrrolidineand 0.4 ml (2.5 mmol) triethylsilane was heated for 1 min at 80° C.,cooled to room temperature and evaporated. Crystallization fromEt₂O/pentane gave 39 mg (54%) of(3R,5S)-1-methanesulfonyl-5-phenoxymethyl-pyrrolidine-3-thiol, mp 78-79°C., MS: 288 (MH⁺).

[0405] In analogy:(2R,4R)-2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethanolgave after TFA/triethylsilane trityl deprotection (Method 3)(3R,5R)-1-methanesulfonyl-5-(2-phenoxy-ethyl)-pyrrolidine-3-thiol, mp82.5-83.5° C., MS: 302 (MH⁺).

Example 10 Ether, O-Carbamate

[0406] A solution of 497 mg (1.5 mmol)(2S,4R)-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-methanolin 9 ml toluene was treated with 0.18 ml (1.65 mmol) phenylisocyanateand 0.18 ml (1.65 mmol) 4-methylmorpholine. The reaction was stirredover night at room temperature and extracted with aqueous 10%KHSO₄/EtOAc (3×). The organic phase was washed with aqueous saturatedNaHCO₃ dried over Na₂SO₄ and evaporated. Flash column chromatography onsilica gel with hexane/EtOAc (4:1 to 2:1) gave 426 mg (63%) ofphenyl-carbamic acid(2S,4R)-1-methanesulfonyl-4-(4-methoxy-benyzlsulfanyl)-pyrrolidin-2-ylmethylester, mp 141.5-142.5° C., MS: 451 (MH⁺).

[0407] TFA/triethylsilane deprotection (Method 2, 8 min refluxed) gavephenyl-carbamic acid(2S,4R)-4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethyl ester in 55%yield, mp 147.5-148.5° C., MS: 331 (MH⁺).

[0408] In analogy:(2R,4R)-2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethanolgave phenyl-carbamic acid(2R,4R)-2-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-ethylester, MS: 456 (M).

[0409] A solution of 150 mg (0.33 mmol) phenyl-carbamic acid(2S,4R)-1-methane-sulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethylester in 1.3 ml DMF was treated at 0° C. with 23.2 mg (0.53 mmol) 55%NaH and 30 min later with 0.2 ml (1.33 mmol) tert-butyl bromoacetate.Over night it was warmed up to room temperature, then extracted withaqueous saturated NH₄Cl/EtOAc (3×). The organic phases were washed withaqueous 10% NaCl, dried (Na₂SO₄) and evaporated. Flash chromatography onsilica gel (EtOAc/hexane ½) gave 179 mg (95%) of(2S,4R)-{[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-ylmethoxycarbonyl]-phenyl-amino}-aceticacid tert-butyl ester, MS: 565 (MH⁺).

[0410] TFA/triethylsilane-deprotection (Method 2, 1 min refluxed) gave(2S,4R)-[(4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxycarbonyl)-phenyl-amino]-aceticacid was received in 50% yield, MS: 389 (MH⁺).

[0411] In analogy:(2R,4R)-2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-ethanolgave via phenyl-carbamic acid(2R,4R)-2-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanyl-pyrrolidin-2-yl]-ethylester with methyl bromoacetate(2R,4R)-({2-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-ethoxycarbonyl}-phenyl-amino)-aceticacid methyl ester, MS: 529 (MH⁺).

Example 11 Ether (Table 1 and Table 2)

[0412] Method A: 9.07 g (20 mmol) of(2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-methanoland 9.5 ml (80 mmol) of benzylbromide were dissolved in 660 ml DMF,cooled to 0° C. and treated with 1.4 g (32 mmol) of 55⁰/o NaH over 15min in 4 portions. The reaction was warmed up over night and treatedwith 4.75 ml (40 mmol) benzylbromide/700 mg (16 mmol) 55% NaH and 6 hlater again with the same amount of benzylbromide/NaH. After further 16h at room temperature the reaction was quenched with saturated NH₄Clsolution/EtOAc (3×). The organic phase was washed with aqueous 10% NaClsoution, dried over Na₂SO₄ and evaporated to give 25 g crude product.Flash-chromatography on silica gel (Hexane/EtOAc 4:1 to 1:4) gave 6.43 g(59%) of(2S,4R)-2-benzyloxymethyl-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidine,MS: 544 (MH⁺). 6.4 g (11.77 mmol)(2S,4R)-2-benzyloxymethyl-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidinewere dissolved in 170 ml TFA and treated at 0° C. with 18.75 ml (117.7mmol) of triethylsilane. After 18 h at 0° C., the mixture was evaporatedand purified by flash-chromatography on silica gel (Hexane/EtOAc 4:1 to1:4) to give 2.66 g (72%) of(3R,5S)-5-benzyloxymethyl-1-methanesulfonyl-pyrrolidine-3-thiol, MS: 302(MH⁺).

[0413] In analogy:(2S,4R)-2-hydroxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidbutyl ester with benzyl bromide gave(2S,4R)-2-benzyloxymethyl-4-mercapto-pyrrolidine-1-carboxylic acid butylester, MS: 324 (MH⁺).

[0414](2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-methanolwith 3-bromo-1-phenyl-1-propene, followed by hydrogenation (17 h) andTFA/triethylsilane deprotection (Method 3) gave(3R,5S)-1-methanesulfonyl-5-(3-phenyl-propoxymethyl)-pyrrolidine-3-thiol,MS: 329 (M).

[0415] Method B: A solution of 0.41 g (0.91 mmol) in 20 ml(bromomethyl)cyclohexane was mixed with 20 ml aqueous 50% NaOH and acatalytic amount of tetrabutyl-ammonium hydrogen sulfate and stirredvigorously over night. The organic phase was separated, and evaporatedon the Kugelrohr. Flash-chromatography on silica gel (hexane/EtOAc 95:5)gave 0.3 g (60%) of(2S,4R)-2-cyclohexylmethoxymethyl-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidine,MS: 550 (MH⁺).

[0416] In analogy to Method 3:(2S,4R)-2-cyclohexylmethoxymethyl-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidinegave(3R,5S)-5-cyclohexylmethoxymethyl-1-methanesulfonyl-pyrrolidine-3-thiol,mp 68-69° C., MS: 308 (MH⁺).

[0417] Following Method A:(2S,4R)-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanoland iodomethane gave after PMB deprotection (Method 1)(3R,5S)-5-methoxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiolas colorless solid, 68-69° C., MS: 338 (MH⁺).

[0418] According to an analogous method the following compounds wereprepared via reacton of(2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-methanoland the 2. educt. mentioned in the following table 1. With chlorides oneequivalent of NaI was added: TABLE 1 PHYSI- CAL Name 2. Educt Method MSCOLOR MP FORM 1 (3R,5S)-5-Benzyloxymethyl-1- BENZYL BROMIDE A 302 M+H+white waxy solid methanesulfonyl-pyrrolidine-3-thiol 2(2S,4R)-3-(4-Mercapto-1-methanesulfonyl- 3-CARBOMETHOXY- A 356 M+H+white waxy solid pyrrolidin-2-ylmethoxymethyl)-benzoic BENZYL BROMIDEacid methyl ester 3 (3R,5S)-1-Methanesulfonyl-5-(pyridin-2- 2-PICOLYLCHLORIDE A 302 M+H+ color-less oil ylmethoxy-methyl)-pyrrolidine-3-thiolHYDROCHLORID trifluoro-acetate (1:1) 4(3R,5S)-1-Methanesulfonyl-5-(pyridin-4- 4-PICOLYL CHLORIDE A 302 M+H+yellow oil ylmethoxymethyl)-pyrrolidine-3-thiol HYDROCHLORIDtrifluoro-acetate (1:1) 5 (3R,5S)-1-Methanesulfonyl-5-prop-2- PROPARGYLA 248 M−H− brown oil ynyloxymethyl-pyrrolidine-3-thiol BROMIDE 6(3R,5S)-1-Methanesulfonyl-5-(pyridin-3- 3-PICOLYL CHLORIDE A 302 M+H+colorless oil ylmethoxy-methyl)-pyrrolidine-3-thiol) HYDROCHLORIDtrifluoro-acetate (1:1) 7 (3R,5S)-1-Methanesulfonyl-5-(naphthalen-2-(BROMOMETHYL)- A 352 M+H+ white 104-106° C. powder2-ylmethoxymethyl)-pyrrolidine-3-thiol NAPHTHALENE 8(3R,5S)-1-Methanesulfonyl-5-(naphthalen- 1-(BROMOMETHYL)- A 352 M+H+white  93-95° C. crystal- 1-ylmethoxymethyl)-pyrrolidine-3-thiolNAPHTHALENE line 9 (3R,5S)-1-Methanesulfonyl-5-(3-methoxy-3-METHOXYBENZYL A 332 M+H+ benzyloxymethyl)-pyrrolidine-3-thiol BROMIDE10 (3R,5S)-5-(4-tert-Butyl-benzyloxymethyl)- 4-TERT-BUTYLBENZYL A 358M+H+ 1-methanesulfonyl-pyrrolidine-3-thiol BROMIDE 11(3R,5S)-1-Methanesulfonyl-5- PENTAFLUOROBENZYL A 392 M+H+pentafluorophenylmethoxymethyl- BROMIDE pyrrolidine-3-thiol 12(3R,5S)-5-(3-Bromo-benzyloxymethyl)-1 3-BROMO BENZYL A 380 M+H+,methanesulfonyl-pyrrolidine-3-thiol BROMIDE 1Br 13(2S,4R)-3-(4-Mercapto-1-methanesulfonyl- 3-CYANO BENZYL A 327 M+H+pyrrolidin-2-ylmethoxymethyl)-benzonitrile BROMIDE 14(3R,5S)-1-Methanesulfonyl-5-(4-methyl- 4-METHYL BENZYL A 316 M+H+benzyloxymethyl)-pyrrolidine-3-thiol BROMIDE 15(3R,5S)-1-Methanesulfonyl-5-(2-methyl- 2-METHYL BENZYL A 316 M+H+benzyloxymethyl)-pyrrolidine-3-thiol BROMIDE 16(3R,5S)-1-Methanesulfonyl-5-(3-methyl- 3-METHYL BENZYL A 316 M+H+benzyloxymethyl)-pyrrolidine-3-thiol BROMIDE 17(3R,5S)-5-(2-Fluoro-benzyloxymethyl)-1- 2-FLUORO BENZYL A 320 M+H+methanesulfonyl-pyrrolidine-3-thiol BROMIDE 18(3R,5S)-5-(3-Fluoro-benzyloxymethyl)-1- 3-FLUORO BENZYL A 320 M+H+methanesulfonyl-pyrrolidine-3-thiol BROMIDE 19 Mixture of(3R,5S)-1-methanesulfonyl-5- (1-BROMOETHYL) A 338 M+Na+ [(R)- and-[(S)-1-phenyl-ethoxymethyl)- BENZENE pyrrolidi 20(3R,5S)-5-(2-Chloro-benzyloxymethyl)-1- 3-CHLOROO BENZYL A 336 M+H+methanesulfonyl-pyrrolidine-3-thiol BROMIDE 21(3R,5S)-5-(2,4-Difluoro-benzyloxymethyl)- 2,4-DIFLUORO BENZYL A 338 M+H+1-methanesulfonyl-pyrrolidine-3-thiol BROMIDE 22(3R,5S)-5-(3-Chloro-benzyloxymethyl)-1- 3-CHLORO BENZYL A 336 M+H+methanesulfonyl-pyrrolidine-3-thiol BROMIDE 23 (3R,5S)-5-(3,5-Dimethyl-3,5-DIMETHYLBENZYL A 330 M+H+ benzyloxymethyl)-1-methanesulfonyl-BROMIDE pyrrolidine-3-thiol 24 (3R,5S)-5-(4-Fluoro-benzyloxymethyl)-1-4-FLUORO BENZYL A 320 M+H+ methanesulfonyl-pyrrolidine-3-thiol BROMIDE25 (3R,5S)-1-Methanesulfonyl-5-(2,3,6- 2,3,5-TRIFLUORO A 356 M+H+trifluoro-benzyloxymethyl)-pyrrolidine-3- BENZYL BROMIDE thiol 26(3R,5S)-5-(3,5-Difluoro-benzyloxymethyl)- 3,5-DIFLUORO BENZYL A 338 M+H+1-methanesulfonyl-pyrrolidine-3-thiol BROMIDE 27(3R,5S)-5-(Biphenyl-4-ylmethoxymethyl)- 4-BIPHENYLMETHYL A 400 M+Na+1-methanesulfonyl-pyrrolidine-3-thiol CHLORIDE 28(3R,5S)-1-Methanesulfonyl-5-(3-phenoxy- 3-PHENOXYBENZYL A 416 M+Na+benzyloxymethyl)-pyrrolidine-3-thiol CHLORIDE 29(3R,5S)-5-(2,5-Difluoro-benzyloxymethyl)- 2,5-DIFLUORO BENZYL A 338 M+H+1-methanesulfonyl-pyrrolidine-3-thiol BROMIDE 30(3R,5S)-5-(3,4-Difluoro-benzyloxymethyl)- 3,4-DIFLUORO BENZYL A 338 M+H+1-methanesulfonyl-pyrrolidine-3-thiol BROMIDE 31(3R,5S)-5-(Benzo[1,3]dioxol-5- 3,4-METHYLENE- A 368 M+Na+ylmethoxymethyl)-1-methanesulfonyl- DIOXYBENZYL pyrrolidine-3-thiolCHLORIDE 32 (3R,5S)-1-Methanesulfonyl-5- 2-PHENYLETHYL B 316 M+H+ brownoil phenethyloxymethyl-pyrrolidine-3-thiol BROMIDE 33(3R,5S)-1-Methanesulfonyl-5-(3-phenyl- CINNAMYL BROMIDE A 329 M brownoil propoxymethyl)-pyrrolidine-3-thiol 34(3R,5S)-5-(2-Fluoro-3-trifluoromethyl- 2-FLUORO-3- A 388 M+H+benzyloxymethyl)-1-methanesulfonyl- TRIFLUORO-BENZYL pyrrolidine-3-thiolBROMIDE 35 (3R,5S)-5-(2-Chloro-6-fluoro- 2-CHLORO-6-FLUORO A 354 M+H+benzyloxymethyl)-1-methanesulfonyl- BENZYL BROMIDE pyrrolidine-3-thiol36 (3R,5S)-5-(2,3-Difluoro-4-trifluoromethyl- 2,3-DIFLUORO-4- A 406 M+H+benzyloxymethyl)-1-methanesulfonyl- TRIFLUOROMETHYLBENZYLpyrrolidine-3-thiol BROMIDE 37 (3R,5S)-1-Methanesulfonyl-5-(2-2-(TRIFLUORO- A 386 M+H+ trifluoromethoxy-benzyloxymethyl)-METHOXY)-BENZYL pyrrolidine-3-thiol BROMIDE 38(3R,5S)-5-(2-Fluoro-5-trifluoromethyl- 2-FLUORO-5- A 388 M+H+benzyloxymethyl)-1-methanesulfonyl- TRIFLUOROBENZYL pyrrolidine-3-thiolBROMIDE 39 (3R,5S)-5-(2-Fluoro-4-trifluoromethyl- 2-FLUORO-4- A 388 M+H+benzyloxymethyl)-1-methanesulfonyl- TRIFLUOROBENZYL pyrrolidine-3-thiolBROMIDE 40 (3R,5S)-5-(2-Fluoro-6-trifluoromethyl- 2-FLUORO-6- A 388 M+H+benzyloxymethyl)-1-methanesulfonyl- TRIFLUOROBENZYL pyrrolidine-3-thiolBROMIDE 41 (3R,5S)-1-Methanesulfonyl-5-(2,4,5- 2,4,5-TRIFLUORO A 356M+H+ trifluoro-benzyloxymethyl)-pyrrolidine-3- BENZYL BROMIDE thiol 42(3R,5S)-5-(2,6-Difluoro-benzyloxymethyl)- 2,6-DIFLUORO BENZYL A 338 M+H+1-methanesulfonyl-pyrrolidine-3-thiol BROMIDE 43(3R,5S)-1-Methanesulfonyl-5-(2,3,4- 2,3,4-TRIFLUORO A 356 M+H+trifluoro-benzyloxymethyl)-pyrrolidine-3- BENZYL BROMIDE thiol 44(3R,5S)-5-(2,3-Difluoro-benzyloxymethyl)- 2,3-DIFLUORO BENZYL A 338 M+H+1-methanesulfonyl-pyrrolidine-3-thiol BROMIDE 45(3R,5S)-1-Methanesulfonyl-5-(2- 2-TRIFLUOROBENZYL A 370 M+H+trifluoromethyl-benzyloxymethyl)- BROMIDE pyrrolidine-3-thiol 46(3R,5S)-5-(2-Bromo-benzyloxymethyl)-1- 2-BROMO BENZYL A 380 M+H+methanesulfonyl-pyrrolidine-3-thiol BROMIDE 1Br 47(3R,5S)-5-(Biphenyl-2-ylmethoxymethyl)- 2-PHENYLBENZYL A 400 M+Na+1-methanesulfonyl-pyrrolidine-3-thiol BROMIDE 48(2S,4R)-2-(4-Mercapto-1-methanesulfonyl- 2-CYANO BENZYL A 327 M+H+pyrrolidin-2-ylmethoxymethyl)-benzonitrile BROMIDE 49(3R,5S)-1-Methanesulfonyl-5-(3,4,5- 3,4,5-TRIFLUORO A 356 M+H+trifluoro-benzyloxymethyl)-pyrrolidine-3- BENZYL BROMIDE thiol 50(3R,5S)-1-Methanesulfonyl-5-(2,3,5- 2,3,5-TRIFLUORO A 356 M+H+trifluoro-benzyloxymethyl)-pyrrolidine-3- BENZYL BROMIDE thiol 51(3R,5S)-1-Methanesulfonyl-5-(2,4,6- 2,4,6-TRIFLUORO A 356 M+H+trifluoro-benzyloxymethyl)-pyrrolidine-3- BENZYL BROMIDE thiol 52(3R,5S)-5-Cyclohexylmethoxymethyl-1- (BROMOMETHYL) B 308 M+H+ white68-69° C. crystal- methanesulfonyl-pyrrolidine-3-thiol CYCLOHEXANE line53 (3R,5S)-5-(5-Chloro-thiophen-2- 2-CHLORO-5- A 341.9 M+H+ colorlessoil ylmethoxymethyl)-1-methanesulfonyl- (CHLOROMETHYL)pyrrolidine-3-thiol THIOPHENE 54 3R,5S)-1-Methanesulfonyl-5-(5-methyl-3-CHLOROMETHYL-5- A 307 M+H+ white 74-75° C. crystal-isoxazol-3-ylmethoxymethyl)-pyrrolidine-3- METHYLISOXAZOLE thiol line 55(3R,5S)-1-Methanesulfonyl-5-(2-methyl- 4-CHLOROMETHYL-2- A 437 M+H+colorless oil thiazol-4-ylmethoxymethyl)-pyrrolidine-3- METHYLTHIAZOLEthiol trifluoro-acetate (1:1) HYDROCHLORIDE

[0419] Further compounds were prepared by reaction of(2S,4R)-2-hydroxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidbutyl ester with the second educt mentioned in table 2: TABLE 2 Name 2.Educt Method MS 1 (2S,4R)-2-Benzyloxymethyl-4-mercapto- BENZYL BROMIDE AM+H+ 324 pyrrolidine-1-carboxylic acid butyl ester 2(2S,4R)-2-(3-Chloro-benzyloxymethyl)-4- 3-CHLORO BENZYL A M+H+ 358mercapto-pyrrolidine-1-carboxylic acid BROMIDE butyl ester 3(2S,4R)-2-(3-Cyano-benzyloxymethyl)-4- 3-CYANO BENZYL A M+H+ 349mercapto-pyrrolidine-1-carboxylic acid BROMIDE butyl ester 4(2S,4R)-2-(3-Bromo-benzyloxymethyl)-4- 3-BROMO BENZYL A M+H+, 1Br 402mercapto-pyrrolidine-1-carboxylic acid BROMIDE butyl ester 5(2S,4R)-2-(3-Fluoro-benzyloxymethyl)-4- 3-FLUORO BENZYL A M+H+ 342mercapto-pyrrolidine-1-carboxylic acid BROMIDE butyl ester 6(2S,4R)-2-(2-Fluoro-benzyloxymethyl)-4- 2-FLUORO BENZYL A M+H+ 342mercapto-pyrrolidine-1-carboxylic acid BROMIDE butyl ester 7(2S,4R)-2-(2,4-Difluoro-benzyloxymethyl)- 2,4-DIFLUORO A M+H+ 3604-mercapto-pyrrolidine-1-carboxylic acid BENZYL BROMIDE butyl ester 8(2S,4R)-2-(2-Chloro-benzyloxymethyl)-4- 2-CHLORO BENZYL A M+H+ 358mercapto-pyrrolidine-1-carboxylic acid BROMIDE butyl ester 9(2S,4R)-2-(4-Bromo-2-fluoro- 4-BROMO-2-FLUORO A M+H+, 1Br 420benzyloxymethyl)-4-mercapto-pyrrolidine- BENZYL BROMIDE 1-carboxylicacid butyl ester 10 (2S,4R)-4-Mercapto-2-(3-methyl- 3-METHYL BENZYL AM+H+ 338 benzyloxymethyl)-pyrrolidine-1-carboxylic BROMIDE acid butylester 11 (2S,4R)-4-Mercapto-2-(2,3,6-trifluoro- 2,3,6-TRIFLUORO A M+H+378 benzyloxymethyl)-pyrrolidine-1-carboxylic BENZYL BROMIDE acid butylester 12 (2S,4R)-2-(3,4-Difluoro-benzyloxymethyl)- 3,4-DIFLUORO A M+H+360 4-mercapto-pyrrolidine-1-carboxylic acid BENZYL BROMIDE butyl ester13 (2S,4R)-2-(4-Fluoro-benzyloxymethyl)-4- 4-FLUORO BENZYL A M+H+ 342mercapto-pyrrolidine-1-carboxylic acid BROMIDE butyl ester 14(2S,4R)-2-(2,5-Difluoro-benzyloxymethyl)- 2,5-DIFLUORO A M+H+ 3604-mercapto-pyrrolidine-1-carboxylic acid BENZYL BROMIDE butyl ester 15(2S,4R)-2-(3-Chloro-2-fluoro-benzyloxymethyl)-4- 3-CHLORO-2FLUORO A M+H+376 mercapto-pyrrolidine-1-carboxylic acid butyl ester BENZYL BROMIDE 16(2S,4R)-2-(2-Cyano-benzyloxymethyl)-4-mercapto- 2-CYANO BENZYL A M+H+349 pyrrolidine-1-carboxylic acid butyl ester BROMIDE 17(2S,4R)-2-(2-Bromo-benzyloxymethyl)-4-mercapto- 2-BROMO BENZYL A M+H+,1Br 402 pyrrolidine-1-carboxylic acid butyl ester BROMIDE 18(2S,4R)-2-(2,3-Difluoro-benzyloxymethyl)-4- 2,3-DIFLUORO A M+H+ 360mercapto-pyrrolidine-1-carboxylic acid butyl ester BENZYL BROMIDE 19(2S,4R)-2-(2-Fluoro-4-trifluoromethyl- 2-FLUORO-4- A M+H+ 410benzyloxymethyl)-4-mercapto-pyrrolidine-1- TRIFLUOROMETHYL carboxylicacid butyl ester BENZYL BROMIDE 20(2S,4R)-4-Mercapto-2-(2,3,5-trifluoro- 2,3,5-TRIFLUORO A M+H+ 378benzyloxymethyl)-pyrrolidine-1-carboxylic acid butyl BENZYL BROMIDEester 21 (2S,4R)-4-Mercapto-2-(2,3,4-trifluoro- 2,3,4-TRIFLUORO A M+H+378 benzyloxymethyl)-pyrrolidine-1-carboxylic acid butyl BENZYL BROMIDEester 22 (2S,4R)-4-Mercapto-2-(3,4,5-trifluoro- 3,4,5-TRIFLUORO A M+H+378 benzyloxymethyl)-pyrrolidine-1-carboxylic acid butyl BENZYL BROMIDEester

Example 12 Ether, Sugar Replacement

[0420] To a solution of(2S,4R)-(4-mercapto-1-methanesulfonyl-pyrrolidin-2-yl)-methanol (0.28 g)in dichloromethane (10 ml) were added pyridine (0.131 g) and aceticanhydride (0.160 g). The reaction mixture was stirred for 4 h at roomtemperature, treated with ice/water and extracted with EtOAc. Theorganic phase was washed with a saturated solution of sodium bicarbonateand brine, dried over magnesium sulphate and concentrated. The residuewas chromatographed on silica gel using EtOAc/hexane 1:2 as eluent toobtain thioacetic acid(3R,5S)-S-(5-hydroxymethyl-1-methanesulfonyl-pyrrolidin-3-yl) ester(0.080 g) as a viscous oil.

[0421] A solution of thioacetic acid(3R,5S)-S-(5-hydroxymethyl-1-methanesulfonyl-pyrrolidin-3-yl) ester(0.070 g) and 1,2,3,4-tetra-O-acetyl-6-deoxy-beta-L-mannopyranose [G.Hodosi and P. Kovac, Carbohydr. Res., 303, 239-243 (1997)] (0.138 g) indichloromethane (10.0 ml) was treated with trimethylsilyltrifluoromethanesulphonate (0.075 ml) at 0° C. The reaction mixture wasstirred at 0° C. for 1 h, poured into a sodium bicarbonate solution, andextracted with EtOAc. The organic phase was washed with brine, driedover magnesium sulphate and concentrated. The residue waschromatographed on silica gel using EtOAc/hexane 1:1 as eluent to obtainacetic acid(2S,3R,4R,5S,6S)-4,5-diacetoxy-2-[(2S,4R)-4-acetylsulfanyl-1-methanesulfonyl-pyrrolidin-2-ylmethoxy]-6-methyl-tetrahydro-pyran-3-ylester (0.105 g) as a syrup, MS: 543 (M+NH₄ ⁺). Acetic acid(2S,3R,4R,5S,6S)-4,5-diacetoxy-2-[(2S,4R)-4-acetylsulfanyl-1-methanesulfonyl-pyrrolidin-2-ylmethoxy]-6-methyl-tetrahydro-pyran-3-ylester (0.080 g) was reacted as described for the S-Acetyl deprotection(see below) to obtain(2S,3R,4R,5R,6S)-2-[(2S,4R)-4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxy]-6-methyl-tetrahydro-pyran-3,4,5-triol(0.035 g) as a colourless foam, MS: 358 (MH⁺).

Example 13 Ether, O-Nonbenzylether

[0422] Following Method A,(2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-methanoland tert-butyl bromoacetate gave(2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy)-aceticacid tert-butyl ester, mp 98° C., slow dec., MS: 568 (MH⁺).

[0423] In analogy:(2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-methanoland methyl (+/−)-2-bromo-4-methylvalerate gave afterflash-chromatography on silica gel (Hexane/EtOAc 9:1 to 3:1) (R)- or(S)-2-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid methyl ester, MS: 582 (MH⁺)

[0424] and (S)- or(R)-2-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid methyl ester, MS: 582 (MH⁺).

[0425] BOC-deprotection (see general method for a selectiveBOC-deprotection):(2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy)-aceticacid tert-butyl ester gave(2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy)-aceticacid, MS: 512 (MH⁺).

[0426] Hydrolysis in EtOH/THF (see General method for hydrolysis of anester): (R)- or(S)-2-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid methyl ester gave (R)- or(S)-2-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid, MS: 568 (MH⁺); and (S)- or(R)-2-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid methyl ester gave (R)- or(S)-2-[(2S,4R)-1-Methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid, MS: 568 (MH⁺).

[0427] EDCI-coupling (see General method for EDCI-coupling) of(2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy)-aceticacid with N-methylbenzylamine gave(2S,4R)-N-benzyl-2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy)-N-methyl-acetamide,MS: 615 (MH⁺).

[0428] Following the TFA/triethylsilane trityl deprotection (Method 3),(2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy)-aceticacid tert-butyl ester gave(2S,4R)-(4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxy)-aceticacid, MS: 268 (M−H)⁻;

[0429] (R)- or(S)-2-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid methyl ester gave (R)- or(S)-2-[(2S,4R)-4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxy]-4methyl-pentanoicacid methyl ester, MS: 340 (MH⁺);

[0430] (S)- or(R)-2-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid methyl ester gave (S)- or(R)-2-[(2S,4R)-4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid methyl ester, MS: 340 (MH⁺);

[0431] (R)- or(S)-2-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid gave (R)- or(S)-2-[(2S,4R)-4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid, MS: 324 (M−H)⁻;

[0432] (R)- or(S)-2-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid gave (S)- or(R)-2-[(2S,4R)-4-Mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxy]-4-methyl-pentanoicacid, MS: 324 (M−H)⁻;

[0433](2S,4R)-N-benzyl-2-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy)-N-methyl-acetamidegave(2S,4R)-N-Benzyl-2-(4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxy)-N-methyl-acetamide,MS: 373 (MH⁺).

[0434] In analogy:(2S,4R)-(1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl)-methanoland methyl (+/−)-alpha-bromophenylacetate gave after the separation ofthe diastereomers and deprotection of the trityl group (Method 3) (R)-or(S)-[(2S,4R)-4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxy]-phenyl-aceticacid methyl ester, MS: 359 (M);

[0435] and (S)- or(R)-[(2S,4R)-4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxy]-phenyl-aceticacid methyl ester, MS: 359 (M).

Example 14 N-Pyrrolidin-Derivatisation of the Ethers

[0436] Starting Materials:

[0437] A solution of 15.5 g (32.59 mmol)(2S,4R)-2-hydroxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidtert-butyl ester and 24.7 g (109.77 mmol) 2,4,5-trifluorobenzylbromidein 700 ml DMF at 0° C. was treated with 2.28 g (52.14 mmol) of 55% NaHin 4 portions and warmed up to room temperature during 7 h. The reactionwas cooled to 0° C. and treated with 500 ml aqueous saturated NH₄Clsolution, extracted with EtOAc (3×). The organic phase was washed with10% NaCl dried over Na₂SO₄ and evaporated. Flash column chromatographyon silica gel with hexane/EtOAc (9:1 to 8.5:1.5) gave 9.37 g (46%) of(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 620 (MH⁺).

[0438] In analogy:(2S,4S)-4-chloro-2-hydroxymethyl-pyrrolidine-1-carboxylic acidtert-butyl ester gave(2S,4S)-4-chloro-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 379 (M).

[0439] A solution of 9.37 g (15.11 mmol)(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester in 30 ml CH₂Cl₂ was treated at −20° C. with 34 mlTFA and warmed up to room temperature during 5.5 h. The reaction wasevaporated and treated with aqueous saturated NaHCO₃ solution/EtOAc (3×)to give 7.77 g (quantitative)(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine,MS: 520 (M).

[0440] In analogy: The reaction of(2S,4R)-2-hydroxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidtert-butyl ester with benzylbromide gave(2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine, MS: 466 (MH⁺).

Example 14.a Ether, Carbamates (Table 3 and Table 4)

[0441] Carbamate, Method A: A solution of 1.9 g (4.1 mmol)(2S,4R)-2-benzyloxy-methyl-4-tritylsulfanyl-pyrrolidine in 25 ml THF at0° C. was treated with 0.57 ml (4.5 mmol) phenyl chloroformate and 0.41ml (5.1 mmol) pyridine. After 2 h at room temperature the reaction wasworked up with 1N HCl/EtOAc (3×), the organic phases were washed withH₂O, aqueous saturated NaHCO₃, dried and evaporated to give 2.6 g(quantitative)(2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidphenyl ester, MS: 586 (MH⁺).

[0442] Trityl deprotection (Method 3) (7 h at 0° C.) gave(2S,4R)-2-benzyloxymethyl-4-mercapto-pyrrolidine-1-carboxylic acidphenyl ester, MS: 343 (M).

[0443] Carbamate, Method B: A solution of 0.19 ml (1.58 mmol)trichloromethyl-chloroformate in 20 ml CH₂Cl₂ was treated at 0° C. with0.28 ml (3 mmol) 2-fluorophenol and 0.35 ml (3 mmol) quinoline and thenstirred for 3 h at room temperature. The reaction was then cooled (0°C.) and a solution of 0.52 g (1 mmol)(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidineand 0.2 ml (2.5 mmol) pyridine in 3 ml CH₂Cl₂ was added, followed by 122mg (1 mmol) DMAP. After 3 h at 0° C. the reaction was evaporated andpoured into aqueous 10% KHSO₄/Et₂O (3×). The organic phases were washedwith aqueous 10% NaCl solution, dried over Na₂SO₄ and evaporated. Flashchromatography on silica gel (hexane/EtOAc 9:1) gave 0.39 g (60%)(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid 2-fluoro-phenyl ester, MS: 658 (MH⁺).

[0444] Trityl deprotection (Method 3) gave(2S,4R)-4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2-fluoro-phenyl ester, MS: 416 (MH⁺).

[0445] In analogy: a)(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidineand DL-Leucyc acid isopropyl ester gave after separation on silica gelwith hexane/EtOAc 9:1(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid (S)- or (R)-1-isopropoxycarbonyl-3-methyl-butyl ester, MS: 720(MH⁺) and(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid (R)- or (S)-1-isopropoxycarbonyl-3-methyl-butyl ester, MS: 720(MH⁺).

[0446](2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidineand ethyl-3-hydroxy-benzoate gave(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid 3-ethoxycarbonyl-phenyl ester, MS: 712 (MH⁺).

[0447](2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidineand ethylglycolate gave(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid ethoxycarbonylmethyl ester, MS: 650 (MH⁺).

[0448] Trityl deprotection (Method 3) of(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid (S)- and (R)-1-isopropoxycarbonyl-3-methyl-butyl ester gave(2S,4R)-4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid (S)- and (R)-1-isopropoxycarbonyl-3-methyl-butyl ester, MS: 478(MH⁺).

[0449] In analogy:(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid 3-ethoxycarbonyl-phenyl ester gave(2S,4R)-4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 3-ethoxycarbonyl-phenyl ester, MS: 470 (MH⁺).

[0450] b) Hydrolysis with 1 N NaOH (see General method for hydrolysis ofan ester) in dioxane of(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid (S)- or (R)-1-isopropoxycarbonyl-3-methyl-butyl ester gave(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid (S)- or (R)-1-carboxy-3-methyl-butyl ester, MS: 678 (MH⁺) and(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid (R)- or (S)-1-isopropoxycarbonyl-3-methyl-butyl ester gave(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid (R)- or (S)-1-carboxy-3-methyl-butyl ester, MS: 678 (MH⁺).

[0451] In analogy:(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid 3-ethoxycarbonyl-phenyl ester gave(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid 3-carboxy-phenyl ester, MS: 684 (MH⁺).

[0452](2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid ethoxycarbonylmethyl ester gave(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid carboxymethyl ester, MS: 620 (M−H)⁻.

[0453] Trityl deprotection (Method 3):(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid (S)- or (R)-1-carboxy-3-methyl-butyl ester gave(2S,4R)-4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid (S)- or (R)-1-carboxy-3-methyl-butyl ester, MS: 434 (M−H⁻) and(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid (R)- or (S)-1-carboxy-3-methyl-butyl ester gave(2S,4R)-4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid (R)- or (S)-1-carboxy-3-methyl-butyl ester, MS: 434 (M−H⁻).

[0454](2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid 3-carboxy-phenyl ester gave(2S,4R)-4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid (S)- or (R)-1-carboxy-3-methyl-butyl ester, MS: 440 (M−H⁻).

[0455](2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid carboxymethyl ester gave(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid carboxymethyl ester, MS: 380 (MH⁺).

[0456] Carbamate, Method C: A solution of 0.07 ml (0.55 mmol)trichloromethyl-chloroformate in 7 ml CH₂Cl₂ was treated at 0° C. with0.13 ml (1.1 mmol) quinoline and after 15 min with 0.52 g (1 mmol)(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidinein 7 ml CH₂Cl₂. After 2 h at 0° C. the CH₂Cl₂ was evaporated. Theresidue was dissolved in 15 ml THF, treated at 0° C. with 0.27 ml (2.1mmol) methyl salicylate, 96 mg (2.4 mmol) of 55% NaH and 166 mg (1 mmol)of KI. The reaction was stirred at room temperature over night, cooled(0° C.) and after the addition of 44 mg (1 mmol) of 55% NaH refluxed for3 h. The reaction was partitioned between aqueous 10% KHSO₄/EtOAc(3×300). The organic phases were washed with aqueous 10% NaCl, dried(Na₂SO₄) and evaporated. Flash chromatography on silica gel(Hexane/EtOAc 9:1) gave 0.48 g (69%)(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid 2-methoxycarbonyl-phenyl ester, MS: 698 (MH⁺).

[0457] (Method 3): A solution of 0.4 g (0.58 mmol)(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid 2-methoxycarbonyl-phenyl ester in 5.8 ml TFA was treated at 0° C.with 0.92 ml (5.78 mmol) triethylsilane and after 10 min at roomtemperature evaporated and purified by flash chromatography on silicagel (Hexane/EtOAc 4:1) to give 0.22 (82%)(2S,4R)-4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2-methoxycarbonyl-phenyl ester, MS: 456 (MH⁺).

[0458] (Method 4): A solution of 0.32 mmol trityl-protected compound wasdissolved in 1.5 ml acetonitril/0.4 ml TFA/0.1 ml triethylsilane andafter 1 night at RT purified by prep HPLC (RP18, CH₃CN/H₂O 80:20 to95:5) to give the free thiols.

[0459] By the reaction of(2S,4R)-2-Benzyloxymethyl-4-tritylsulfanyl-pyrrolidine with the secondeduct in table 3 the following compounds were obtained: TABLE 3 Name 2.Educt Method MS 1 (2S,4R)-2-Benzyloxymethyl-4-mercapto- PHENYLCHLOROFORMATE A M 343 pyrrolidine-1-carboxylic acid phenyl ester 2(2S,4R)-2-Benzyloxymethyl-4-mercapto- ISOPROPYL A M+H+ 310pyrrolidine-1-carboxylic acid isopropyl ester CHLOROFORMATE 3(2S,4R)-2-Benzyloxymethyl-4-mercapto- 2-CHLOROETHYL A M+H+ 330pyrrolidine-1-carboxylic acid 2-chloro-ethyl ester CHLOROFORMATE 4(2S,4R)-2-Benzyloxymethyl-4-mercapto- BENZYL CHLOROFORMATE A M+H+ 358pyrrolidine-1-carboxylic acid benzyl ester 5(2S,4R)-2-Benzyloxymethyl-4-mercapto- CHLOROFORMIC ACID 2- A M+H+ 394pyrrolidine-1-carboxylic acid naphthalen-2-yl ester NAPHTHYL ESTER 6(2S,4R)-2-Benzyloxymethyl-4-mercapto- CHLOROFORMIC ACID N- A M+H+ 338pyrrolidine-1-carboxylic acid pentyl ester AMYL ESTER 7(2S,4R)-2-Benzyloxymethyl-4-mercapto- ISOBUTYL CHLOROFORMATE A M+H+ 324pyrrolidine-1-carboxylic acid isobutyl ester 8(2S,4R)-2-Benzyloxymethyl-4-mercapto- METHYL CHLOROFORMATE A M 281pyrrolidine-1-carboxylic acid methyl ester 9(2S,4R)-2-Benzyloxymethyl-4-mercapto- BUTYL CHLOROFORMATE A M+H+ 324pyrrolidine-1-carboxylic acid butyl ester

[0460] By the reaction of(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidinewith the second educt mentioned in table 4 the following compounds wereobtained: TABLE 4 Name 2. Educt Method MS 1(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- ISOPROPYL A M+H+ 364benzyloxymethyl)-pyrrolidine-1-carboxylic acid CHLOROFORMATE isopropylester 2 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- PHENYL CHLOROFORMATE AM+H+ 398 benzyloxymethyl)-pyrrolidine-1-carboxylic acid phenyl ester 3(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2-CHLOROETHYL A M+H+ 384benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2- CHLOROFORMATEchloro-ethyl ester 4 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- BENZYLCHLOROFORMATE A M+H+ 412 benzyloxymethyl)-pyrrolidine-1-carboxylic acidbenzyl ester 5 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- CHLOROFORMIC ACID2- A M+H+ 448 benzyloxymethyl)-pyrrolidine-1-carboxylic acid NAPHTHYLESTER naphthalen-2-yl ester 6 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-CHLOROFORMIC ACID N- A M+H+ 392benzyloxymethyl)-pyrrolidine-1-carboxylic acid AMYL ESTER pentyl ester 7(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- ISOBUTYL CHLOROFORMATE A M+H+ 378benzyloxymethyl)-pyrrolidine-1-carboxylic acid isobutyl ester 8(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- METHYL CHLOROFORMATE A M+H+ 336benzyloxymethyl)-pyrrolidine-1-carboxylic acid methyl ester 9(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 4-FLUOROPHENYL A M+H+ 416benzyloxymethyl)-pyrrolidine-1-carboxylic acid 4- CHLOROFORMATEfluoro-phenyl ester 10 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- Lit [1] AM+H+ 456 benzyloxymethyl)-pyrrolidine-1-carboxylic acid2,3-dihydro-benzo[1,4]dioxin-5-yl ester 11(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 4-METHOXYCARBONYL- A M+H+ 456benzyloxymethyl)-pyrrolidine-1-carboxylic acid 4- PHENYL CHLOROFORMATEmethoxycarbonyl-phenyl ester 12 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-4-CHLOROPHENYL A M+H+ 432 benzyloxymethyl)-pyrrolidine-1-carboxylic acid4- CHLOROFORMATE chloro-phenyl ester 13(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- P-TOLYL CHLOROFORMATE A M+H+ 412benzyloxymethyl)-pyrrolidine-1-carboxylic acid p- tolyl ester 14(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 4-BROMOPHENYL A M+H+, 476benzyloxymethyl)-pyrrolidine-1-carboxylic acid 4- CHLOROFORMATE 1Brbromo-phenyl ester 15 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- PROPARGYL AM+H+ 36 benzyloxymethyl)-pyrrolidine-1-carboxylic acid CHLOROFORMATEprop-2-ynyl ester 16 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 3-BUTENYL AM+H+ 376 benzyloxymethyl)-pyrrolidine-1-carboxylic acid CHLOROFORMATEbut-3-enyl ester 17 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- (−)-MENTHYL AM+H+ 460 benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2- CHLOROFORMATEisopropyl-5-methyl-cyclohexyl ester 18(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- PHENETHYLALCOHOL B M+H+ 426benzyloxymethyl)-pyrrolidine-1-carboxylic acid phenethyl ester 19(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2,2,2-TRIFLUORETHANOL B M 403benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2,2,2-trifluoro-ethylester 20 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 4-METHOXYPHENYL A M+H+428 benzyloxymethyl)-pyrrolidine-1-carboxylic acid 4- CHLOROFORMATEmethoxy-phenyl ester 21 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-CHLOROFORMIC ACID 2- A M+H+ 380benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2- METHOXYETHYL ESTERmethoxy-ethyl ester 22 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- BUTYLCHLOROFORMATE A M+H+ 370 benzyloxymethyl)-pyrrolidine-1-carboxylic acidbutyl ester 23 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- ETHYLCHLOROFORMATE A M+H+ 350 benzyloxymethyl)-pyrrolidine-1-carboxylic acidethyl ester 24 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- PROPYLCHLOROFORMATE A M+H+ 364 benzyloxymethyl)-pyrrolidine-1-carboxylic acidpropyl ester 25 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- ETHYLGLYCOLATE BM+H+ 408 benzyloxymethyl)-pyrrolidine-1-carboxylic acidethoxycarbonylmethyl ester 26 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-CHLOROFORMIC ACID N- A M+H+ 406benzyloxymethyl)-pyrrolidine-1-carboxylic acid HEXYL ESTER hexyl ester27 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2-FLUOROBENZYL ALCOHOL B M+H+430 benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2- fluoro-benzylester 28 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2-FLUOROPHENOL B,described M+H+ 416 benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2-fluoro-phenyl ester 29 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-BOC-AMINOETHANOL C M+H+ 365 benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2- amino-ethyl ester; compound with trifluoro-acetic acid 30(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 4-(HYDROXYMETHYL) B M+H+ 413benzyloxymethyl)-pyrrolidine-1-carboxylic acid PYRIDINEpyridin-4-ylmethyl ester; compound with trifluoro- acetic acid 31(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2-METHYLPHENOL B M+H+ 412benzyloxymethyl)-pyrrolidine-1-carboxylic acid o- tolyl ester 32(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2-METHOXYPHENOL B M+H+ 428benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2- methoxy-phenyl ester33 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- METHYL SALICYLATE C, describedM+H+ 456 benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2-methoxycarbonyl-phenyl ester 34 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-2-DIMETHYLAMINOETHANOL B M+H+ 393benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2- dimethylamino-ethylester; compound with trifluoro-acetic acid 35(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2-HYDROXYBENZONITRILE B M+H+ 423benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2- cyano-phenyl ester 36(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 3-FLUOROPHENOL B M+H+ 416benzyloxymethyl)-pyrrolidine-1-carboxylic acid 3- fluoro-phenyl ester 37(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2-BROMOPHENOL B M+H+ 477benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2- bromo-phenyl ester 38(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 1-NAPHTHALENEMETHANOL B M+H+ 462benzyloxymethyl)-pyrrolidine-1-carboxylic acid naphthalen-1-ylmethylester 39 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2-NAPHTHALENEETHANOL BM+H+ 476 benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2-naphthalen-2-yl-ethyl ester 40 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-1-NAPHTHALENEETHANOL B M+H+ 476benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2- naphthalen-1-yl-ethylester 41 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 3-PHENOXYPHENOL B M+H+490 benzyloxymethyl)-pyrrolidine-1-carboxylic acid 3- phenoxy-phenylester 42 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 3-PHENYLPHENOL B M+H+474 benzyloxymethyl)-pyrrolidine-1-carboxylic acid biphenyl-3-yl ester43 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 4-CYCLOHEXYLPHENOL B M+H+ 480benzyloxymethyl)-pyrrolidine-1-carboxylic acid 4- cyclohexyl-phenylester 44 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2-PHENYLPHENOL B M+H+474 benzyloxymethyl)-pyrrolidine-1-carboxylic acid biphenyl-2-yl ester45 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 5,6,7,8-TETRAHYDRO-1- B M+H+452 benzyloxymethyl)-pyrrolidine-1-carboxylic acid NAPHTHOL5,6,7,8-tetrahydro-naphthalen-1-yl ester 46(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2-NAPHTHALENEMETHANOL B M+H+ 462benzyloxymethyl)-pyrrolidine-1-carboxylic acid naphthalen-2-ylmethylester 47 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 4-PHENYLPHENOL B M+H+474 benzyloxymethyl)-pyrrolidine-1-carboxylic acid biphenyl-4-yl ester48 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 2CHLOROPHENOL B M+H+ 432benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2- chloro-phenyl ester 49(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 5-HYDROXYISOQUINOLINE B M+H+ 563benzyloxymethyl)-pyrrolidine-1-carboxylic acid isoquinolin-5-yl ester;compound with trifluoro- acetic acid 50(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 4-HYDROXYQUINOLINE B M+H+ 563benzyloxymethyl)-pyrrolidine-1-carboxylic acid quinolin-4-yl estertrifluoroacetate (1:1) 51 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-8-HYDROXYQUINOLINE B M+H+ 563 benzyloxymethyl)-pyrrolidine-1-carboxylicacid quinolin-8-yl ester trifluoroacetate (1:1) 52(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 5-HYDROXYQUINOLINE B M+H+ 563benzyloxymethyl)-pyrrolidine-1-carboxylic acid quinolin-5-yl estertrifluoroacetate (1:1) 53 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-ISOCARBOSTYRIL B M+H+ 563 benzyloxymethyl)-pyrrolidine-1-carboxylic acidisoquinolin-1-yl ester trifluoroacetate (1:1) 54(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- Lit [2] B M+H+ 442benzyloxymethyl)-pyrrolidine-1-carboxylic acid benzo[1,3]dioxol-4-ylester 55 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 1-NAPHTOL B M+H+ 448benzyloxymethyl)-pyrrolidine-1-carboxylic acid naphthalen-1-yl ester 56(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 3-HYDROXYPYRIDINE B M+H+ 513benzyloxymethyl)-pyrrolidine-1-carboxylic acid pyridin-3-yl estertrifluoroacetate (1:1) 57 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-2-HYDROXYPYRIDINE B M+H+ 513 benzyloxymethyl)-pyrrolidine-1-carboxylicacid pyridin-2-yl ester trifluoroacetate (1:1) 58(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 6-HYDROXYQUINOLINE B M+H+ 563benzyloxymethyl)-pyrrolidine-1-carboxylic acid quinolin-6-yl estertrifluoroacetate (1:1) 59 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-5-(2-HYDROXYETHYL)-4- B M+H+ 561benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2- METHYLTHIAZOLE(4-methyl-thiazol-5-yl)-ethyl ester trifluoroacetate (1:1) 60(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 4-PYRIDINEPROPANOL B M+H+ 555benzyloxymethyl)-pyrrolidine-1-carboxylic acid 3- pyridin-4-yl-propylester trifluoroacetate (1:1) 61 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-PYRIDINE-2-METHANOL B M+H+ 527 benzyloxymethyl)-pyrrolidine-1-carboxylicacid pyridin-2-ylmethyl ester 62 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-2-CHLOROOPHENOL B M+H+ 432 benzyloxymethyl)-pyrrolidine-1-carboxylicacid 3- chloro-phenyl ester 63 (2S,4R,3R)-4-Mercapto-2-(2,4,5-trifluoro-Lit [3] B M+H+ 526 benzyloxymethyl)-pyrrolidine-1-carboxylic acid(R)-1-benzyloxycarbonyl-3-methyl-butyl ester 64(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 5,7-DICHLORO-8- B M+H+ 632benzyloxymethyl)-pyrrolidine-1-carboxylic acid HYDROXYQUINOLINE5,7-dichloro-quinolin-8-yl ester; compound with trifluoro-acetic acid 65(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- CYCLOHEXYL A M+H+ 404benzyloxymethyl)-pyrrolidine-1-carboxylic acid CHLOROFORMATE cyclohexylester 66 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 3-Methoxy-phenol B M+H+428 benzyloxymethyl)-pyrrolidine-1-carboxylic acid 3- methoxy-phenylester 67 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- 3,4-Dimethoxy-phenol CM+H+ 458 benzyloxymethyl)-pyrrolidine-1-carboxylic acid3,4-dimethoxy-phenyl ester 68 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- CM−H− 440 benzyloxymethyl)-pyrrolidine-1-carboxylic acid 2-carboxy-phenyl ester

[0461] [1] 5-(1,4-benzodioxan)-chloroformate: Eitel, Alfred; Hammann,Ingeborg. Benzodioxan-N-methylcarbamates useful as insecticides oracaricides. S. African, 14 pp. CODEN: SFXXAB. ZA 6800512 680627. CAN70:57861 CAPLUS

[0462] [2] Benzo[1,3]dioxol-4-ol: Dallacker, Franz; Holschbach, Markus;Holschbach, Ute; Konings, A. W. T. 1,3-Benzo-dioxole derivatives asradioprotectants. 5. Preparation of 4- and 5-hydroxy-1,3-benzodioxolederivatives. Chem.-Ztg. (1990), 114(7-8), 225-8.

[0463] [3] (2R)-2-Hydroxy-4-methyl-pentanoic acid benzyl ester: Brown,Frank K.; Brown, Peter J.; Bickett, D. Mark; Chambers, C. Lynn; Davies,H. Geoff; Deaton, David N.; Drewry, David; Foley, Michael; McElroy,Andrew B.; et al. Matrix Metalloproteinase Inhibit

[0464] [4] 2-Hydroxy-benzoic acid tert-butyl ester: Widmer, Ulrich. Aconvenient preparation of tert-butyl esters. Synthesis (1983), Issue 2,135-6.

Example 14.b Ether, Carbamate via Thioacetate

[0465] A solution of 0.873 mg (2 mmol)(2S,4S)-4-chloro-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester was dissolved in 20 ml DMF and after the additionof 0.343 mg (3 mmol) potassium thioacetate heated for 2.5 h at 100° C.Evaporation and flash-chromatography on silica gel (toluene/CH₃CN 95:5)gave 0.745 g (89%) of(2R,4S)-4-acetylsulfanyl-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 420 (MH⁺).

Example 14.c Deprotection of Thioacetate

[0466] A solution of 0.126 g (0.3 mmol)(2R,4S)-4-acetylsulfanyl-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester in 12 ml EtOH (degased with Ar) was treated at 0°C. with 0.9 ml IN LiOH, warmed up to room temperature and stirred for4.5 h. The reaction was recooled to 0° C. and quenched with aqueous 10%KHSO₄. The reaction was extracted with aqueous 10% KHSO₄/EtOAc (3×) andthe organic phase was washed with aqueous 10% NaCl, dried over Na₂SO₄and evaporated to give 0.11 g (97%)(2S,4R)-4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 378 (MH⁺).

Example 14.d Ether, Sulfonamides (see Table 5 and Table 6)

[0467] General procedure for the synthesis of sulfonamides: A solutionof 0.32 mmol (2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine or(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine,65 μl (0.38 mmol) diisopropylethylamine and a catalytic amount of DMAPin 2 ml dichloroethane was added to 1.2 eq sulfonylchloride. After anight, the reaction was evaporated, redissolved in DMF and purified bypreparative HPLC.

[0468] Trityl deprotection following Method 4 gave the free thiol.

[0469] In analogy:(2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine and2,4-dioxo-1,4-dihydro-2H-benzo [d][1,3]oxazine-6-sulfonyl chloride[Ferrini et al. Eur. Pat. Appl. No. 800220] gave(2S,4R)-6-(2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-sulfonyl)-1H-benzo[d][1,3]oxazine-2,4-dione, MS: 689(M−H⁻), which was deprotected (followingMethod 3) to give(2S,4R)-6-(2-benzyloxymethyl-4-mercapto-pyrrolidine-1-sulfonyl)-1H-benzo[d][1,3]oxazine-2,4-dione, MS: 447 (M−H⁻).

[0470] A solution of 0.72 g (1.05 mmol)(2S,4R)-6-(2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-sulfonyl)-1H-benzo[d][1,3]oxazine-2,4-dione in 40 ml CH₂Cl₂ was treated at room temperaturewith 0.42 ml (10.5 mmol) MeOH and 0.31 ml (2.09 mmol) DBU and stirredfor 6 h. Flash chromatography on silica gel (Hexane/EtOAc 9:1) gave(2S,4R)-2-amino-5-[2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-sulfonyl]-benzoicacid methyl ester which was deprotected (following Method 3) to give(2S,4R)-2-amino-5-[2-benzyloxymethyl-4-mercapto-pyrrolidine-1-sulfonyl]-benzoicacid methyl ester, MS: 437 (M+H⁺).

[0471] A solution of 0.70 g (1.05 mmol)(2S,4R)-6-(2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-sulfonyl)-1H-benzo[d] [1,3] oxazine-2,4-dione in 30 ml dioxane Was treated at 8° C. with2.1 ml (2.09 mmol) aqueous LiOH and stirred for 16 h at roomtemperature. The reaction was evaporated, extracted with aqueous 10%KHSO₄/EtOAc (3×) and the organic phase was dried over Na₂SO₄ to giveafter evaporation and trityl deprotection (following Method 3) 96 mg mg(21%) of(2S,4R)-2-Amino-5-[2-benzyloxymethyl-4-mercapto-pyrrolidine-1-sulfonyl]-benzoicacid, MS: 423 (M+H⁺).

[0472] In analogy to the general procedure:(2S,4R)-2-Benzyloxymethyl-4-tritylsulfanyl-pyrrolidine andalpha-bromophenylacetic acid gave a 1:1 mixture of (R)- and(S)-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-yl whichwas esterified with MeOH (see general method for EDCI-coupling takingDMAP instead of HOBT) to give after flash chromatography on silica gel(hexane/EtOAc) (R)- or(S)-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-phenyl-aceticacid methyl ester, MS: 602 (MH⁺) and (S)- or(R)-[(2S,4R)-1-methanesulfonyl-4-tritylsulfanyl-pyrrolidin-2-ylmethoxy]-phenyl-aceticacid methyl ester, MS: 602 (MH⁺).

[0473] Trityl deprotection (following Method 3) gave: (R)- or(S)-[(2S,4R)-4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxy]-phenyl-aceticacid methyl ester, MS: 359 (M) and (S)- or(R)-[(2S,4R)-4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethoxyl]-phenyl-aceticacid methyl ester, MS: 359 (M).

[0474] By the reaction of(2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine with the secondeduct mentioned in table 5 the following compounds were obtained: TABLE5 Name 2. Educt MS 1 (2S,4R)-N-[4-(2-Benzyloxymethyl-4-mercapto-4-ACETAMIDOBENZENESULFONYL M+H+ 421pyrrolidine-1-sulfonyl)-phenyl]-acetamide CHLORIDE 2(3R,5S)-5-Benzyloxymethyl-1-(3-nitro- 3-NITROBENZENESULFONYL M+Na+ 431benzenesulfonyl)-pyrrolidine-3-thiol CHLORIDE 3(3F,5S)-5-Benzyloxymethyl-1-(2-nitro- 2-NITROBENZENESULFONYL M+H+ 409benzenesulfonyl)-pyrrolidine-3-thiol CHLORIDE 4(3R,5S)-5-Benzyloxymethyl-1-(4- 4-METHYLSULPHONYL- M+Na+ 464methanesulfonyl-benzenesulfonyl)-pyrrolidine- BENZENESULPHONYL CHLORIDE3-thiol 5 (3R,5S)-5-Benzyloxymethyl-1-(biphenyl-4- 4-BIPHENYLSULFONYLCHLORIDE M+H+ 440 sulfonyl)-pyrrolidine-3-thiol 6(3R,5S)-5-Benzyloxymethyl-1-(2-naphthalen-1-2-(1-NAPHTHYL)ETHANESULFONYL 442 M+H+yl-ethanesulfonyl)-pyrrolidine-3-thiol CHLORIDE 7(3R,5S)-5-Benzyloxymethyl-1-(3,5-dimethyl- 3,5-DIMETHYLISOXAZOLE-4- 383M+H+ isoxazole-4-sulfonyl)-pyrrolidine-3-thiol SULFONYL CHLORIDE 8(3R,5S)-5-Benzyloxymethyl-1-(thiophene-2- THIOPHENE-2-SULFONYL CHLORIDE370 M+H+ sulfonyl)-pyrrolidine-3-thiol 9(3R,5S)-1-Benzenesulfonyl-5-benzyloxymethyl- BENZENESULFONYL CHLORIDE364 M+H+ pyrrolidine-3-thiol 10 (3R,5S)-5-Benzyloxymethyl-1-(3-chloro-2-CHLOROBENZENESULFONYL 398 M+H+ benzenesulfonyl)-pyrrolidine-3-thiolCHLORIDE 11 (3R,5S)-5-Benzyloxymethyl-1-(2-phenyl-TRANS-BETA-STYRENESULFONYL 390 M+H+ ethenesulfonyl)-pyrrolidine-3-thiolCHLORIDE 12 (3R,5S)-5-Benzyloxymethyl-1-(propane-2- ISOPROPYLSULFONYLCHLORIDE 352 M+Na+ sulfonyl)-pyrrolidine-3-thiol 13(3R,5S)-5-Benzyloxymethyl-1-(4-fluoro- 4-FLUOROBENZENESULFONYL 382 M+H+benzenesulfonyl)-pyrrolidine-3-thiol CHLORIDE 14(3R,5S)-5-Benzyloxymethyl-1-(quinoline-8- 8-QUINOLINESULFONYL CHLORIDE415 M+H+ sulfonyl)-pyrrolidine-3-thiol 15 Mixture of(3R,5S)-1-methanesulfonyl-5-[(R)- (1-BROMOETHYL)BENZENE 338 M+Na+ and-[(S)-1-phenyl-ethoxymethyl)-pyrrolidi 16(2S,4R)-6-(2-Benzyloxymethyl-4-mercapto- Lit [1] described 447 M−H−pyrrolidine-1-sulfonyl)-1H-benzo[d][1,3]oxazine- 2,4-dione

[0475] [1] 2,4-Dioxo-1,4-dihydro-2H-benzo[d] [1,3]oxazine-6-sulfonylchloride: Ferrini, Pier Giorgio; Rossi, Alberto; Haas, Georges.Substituted anthranilic acid amides. Eur. Pat. Appl., 40 pp. CODEN:EPXXDW. EP 8072 800220. CAN 93:71808 CAPLUS.

[0476] By the reaction of(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine66-7030 with the second educt mentioned in table 6 the followingcomounds were obtained: TABLE 6 Name 2. Educt MS 1(3R,5S)-1-(Thiophene-2-sulfonyl)-5-(2,4,5- THIOPHENE-2-SULFONYL CHLORIDEM+H+ 424 trifluoro-benzyloxymethyl)-pyrrolidine-3-thio 2(3R,5S)-1-(2-Naphthalen-1-yl-ethanesulfonyl)-5-2-(1-NAPHTHYL)ETHANESULFONYL M+H+ 496(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-3- CHLORIDE thiol 3(3R,5S)-1-(2-Phenyl-ethenesulfonyl)-5-(2,4,5- TRANS-BETA-STYRENESULFONYLM+H+ 444 trifluoro-benzyloxymethyl)-pyrrolidine-3-t CHLORIDE 4(3R,5S)-1-(Naphthalene-1-sulfonyl)-5-(2,4,5- 1-NAPHTHALENESULFONYL M+H+468 trifluoro-benzyloxymethyl)-pyrrolidine-3-thiol CHLORIDE 5(3R,5S)-1-(2-Phenyl-ethanesulfonyl)-5-(2,4,5- Lit [1] M+H+ 446trifluoro-benzyloxymethyl)-pyrrolidine-3-t 6(3R,5S)-1-(3-Phenyl-propane-1-sulfonyl)-5- 3-PHENYL-PROPANE-1-SULFONYLM+H+ 460 (2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine CHLORIDE 7(3R,5S)-1-Ethanesulfonyl-5-(2,4,5-trifluoro- ETHANESULFONYL CHLORIDEM+H+ 370 benzyloxymethyl)-pyrrolidine-3-thiol 8(3R,5S)-1-(Propane-1-sulfonyl)-5-(2,4,5- 1-PROPANESULFONYL CHLORIDE M+H+384 trifluoro-benzyloxymethyl)-pyrrolidine-3-thiol 9(3R,5S)-1-(Butane-1-sulfonyl)-5-(2,4,5-trifluoro- 1-BUTANESULFONYLCHLORIDE M+H+ 398 benzyloxymethyl)-pyrrolidine-3-thiol 10(3R,5S)-1-(Quinoline-8-sulfonyl)-5-(2,4,5- 8-QUINOLINESULFONYL CHLORIDEM+H+ 469 trifluoro-benzyloxymethyl)-pyrrolidine-3-thio 11(2S,4R)-N-{4-[4-Mercapto-2-(2,4,5-trifluoro- 4-ACETAMIDOBENZENESULFONYLM+H+ 475 benzyloxymethyl)-pyrrolidine-1-sulfonyl]- CHLORIDEphenyl}-acetamide 12 (2S,4R)-2-Ethoxy-5-[4-mercapto-2-(2,4,5- Lit [2]M+H+ 506 trifluoro-benzyloxymethyl)-pyrrolidine-1- sulfonyl]-benzoicacid

[0477] [1] 2-Phenyl-ethanesulfonyl chloride: Zhong, Ziyang; Bibbs,Jeffrey A.; Yuan, Wei; Wong, Chi Huey. Active-site-directed modificationof subtilisin. J. Am. Chem. Soc. (1991), 113(6), 2259-63. CODEN: JACSAT;ISSN: 0002-7863. CAN 114:123036 CAPLUS.

[0478] [2] 5-Chlorosulfonyl-2-ethoxy-benzoic acid: Dunn, Peter James;Wood, Albert Shaw. Process for preparation of Sildenafil by cyclization.Eur. Pat. Appl., 18 pp. CODEN: EPXXDW. EP 812845 A1 971217. CAN128:75412 CAPLUS.

Example 14.e Ether: Ureas (Table 7 and Table 8)

[0479] A solution of 50 mg (0.11 mmol) amine in 0.5 ml EtOH was treatedwith 0.21 mmol of the appropriate isocyanate, the reaction was kept 30min at room temperature and purified by preparative HPLC (RP18,CH₃CN/H₂O 80:20 to 95:5). Trityl deprotection following Method 4 gavethe free thiol.

[0480] A solution of 0.02 ml (0.18 mmol) trichloromethylchloroformate in3 ml CH₂Cl₂ was treated at 0° C. with 0.04 ml (0.37 mmol) quinoline andafter 15 min with 0.17 g (0.33 mmol)(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidinein 2 ml CH₂Cl₂. After 2 h, the reaction was evaporated and redissolvedin 15 ml CH₂Cl₂ and treated at 0° C. with 0.14 ml (1.65 mmol)pyrrolidine and stirred for 30 min. The reaction was extracted withaqueous 10% KHSO₄/Et₂O (3×) and the organic phase was dried over Na₂SO₄.Evaporation and precipitation from Et₂O/pentane gave 121 mg (59%)(2S,4R)-Pyrrolidin-1-yl-[2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidin-1-yl]-methanone,MS: 617 (M+H⁺).

[0481] Trityl deprotection (following Method 3) gave(2S,4R)-[4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]-pyrrolidin-1-yl-methanone,MS: 374 (M).

[0482] By the reaction of(2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine with the secondeduct of table 7 the following compound have been obtained: TABLE 7 Name2. Educt MS 1 (2S,4R)-[(2-Benzyloxymethyl-4-mercapto- ETHYLISOCYANATOACETATE M+H+ 353 pyrrolidine-1-carbonyl)-amino]-acetic acidethyl ester 2 (2S,4R)-2-Benzyloxymethyl-4-mercapto- ′PHENYL ISOCYANATEM+H+ 343 pyrrolidine-1-carboxylic acid phenylamide 3(2S,4R)-2-Benzyloxymethyl-4-mercapto- 2-FLUOROPHENYL ISOCYANATE M+H+ 361pyrrolidine-1-carboxylic acid (2-fluoro-phenyl)- amide 4(2S,4R)-2-Benzyloxymethyl-4-mercapto- 2,4-DIFLUOROPHENYL M+H+ 379pyrrolidine-1-carboxylic acid (2,4-difluoro-phenyl)- ISOCYANATE amide 5(2S,4R)-(2-Benzyloxymethyl-4-mercapto- ′ETHOXYCARBONYL ISOCYANAT M+Na+361 pyrrolidine-1-carbonyl)-carbamic acid ethyl ester 6(2S,4R)-2-Benzyloxymethyl-4-mercapto- 3-CYANOROPHENYL ISOCYANATE M+H+368 pyrrolidine-1-carboxylic acid (3-cyano-phenyl)- amide 7(2S,4R)-2-Benzyloxymethyl-4-mercapto- ′4-ACETYLPHENYL ISOCYANATE M+H+385 pyrrolidine-1-carboxylic acid (4-acetyl-phenyl)- amide 8 1:1 Mixtureof (R)- and (S)-2-[[(2S,4R)-2- ETHYL 2-ISOCYANATO-3- M+Na+ 465benzyloxymethyl-4-mercapto-pyrrolidine-1- PHENYLPROPIONATEcarbonyl)-amino]-3-phenyl-propionic acid ethyl ester 9(2S,4R)-2-Benzyloxymethyl-4-mercapto- ′BENZYL ISOCYANATE M+H+ 357pyrrolidine-1-carboxylic acid benzylamide 10(2S,4R)-2-Benzyloxymethyl-4-mercapto- 3-TRIFLUOROPHENYL M+H+ 411pyrrolidine-1-carboxylic acid (3-trifluoromethyl- ISOCYANATEphenyl)-amide 11 (2S,4R)-2-Benzyloxymethyl-4-mercapto- ′PHENETHYLISOCYANATE M+H+ 371 pyrrolidine-1-carboxylic acid phenethyl-amide 12(2S,4R)-2-Benzyloxymethyl-4-mercapto- ′2-NAPHTHYL ISOCYANATE M+H+ 393pyrrolidine-1-carboxylic acid naphthalen-2-ylamide 13(2S,4R)-2-Benzyloxymethyl-4-mercapto- 1-NAPHTHYL ISOCYANATE M+H+ 393pyrrolidine-1-carboxylic acid naphthalen-1-ylamide

[0483] By the reaction of(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidinewith the second educt mentioned in table 8 the following compound wereobtained: TABLE 8 Name 2. Educt MS 1(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)- 2-FLUOROPHENYLM+H+ 415 pyrrolidine-1-carboxylic acid (2-fluoro-phenyl)-amideISOCYANATE 2 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-′2-NAPHTHYL ISOCYANATE M+H+ 447 pyrrolidine-1-carboxylic acidnaphthalen-2-ylamide 3(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)- 1-NAPHTHYLISOCYANATE M+H+ 447 pyrrolidine-1-carboxylic acid naphthalen-1-ylamide 4(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)- ′PHENETHYLISOCYANATE M+H+ 425 pyrrolidine-1-carboxylic acid phenethyl-amide 5(2S,4R)-[4-Mercapto-2-(2,4,5-trifluoro- ′ETHOXYCARBONYL M+H+ 393benzyloxymethyl)-pyrrolidine-1-carbonyl]-carbamic acid ISOCYANAT ethylester 7 (2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)- ′PHENYLISOCYANATE M+H+ 397 pyrrolidine-1-carboxylic acid phenylamide 8(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)- N-BUTYLISOCYANATE M+H+ 377 pyrrolidine-1-carboxylic acid butylamide 6(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)- ′BENZYLISOCYANATE M+H+ 411 pyrrolidine-1-carboxylic acid benzylamide

Example 14.f Alkylation of Ureas

[0484] A solution of the urea in DMF (20 ml/mmol) was placed in an icebath. KOtBu (1.2 eq.) was added and stirred for 15 min. MeI (1.1 eq.)was added and stirred overnight at room temperature. If required, afurther 1 eq. of KOtBu and MeI was added and stirred overnight at roomtemperature. Water was added and the mixture was extracted withdichloromethane. The organic phase was dried (Na₂SO₄), filtered andevaporated. The product was purified by chromatography (SiO₂,EtOAc/hexane 9:1=>hexane/EtOAc 1:1).

[0485] Benzyl-methyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid benzyl-methyl-amide; yield: 53%;

[0486] Butyl-methyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid butyl-methyl-amide; yield: 52%.

[0487] Trityl deprotection (Method 3):

[0488] Butyl-methyl:(2S,4R)-4″-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid butyl-methyl-amide; colorless oil; yield: 76%, MS: 391 (MH⁺);

[0489] Benzyl-methyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid benzyl-methyl-amide; colorless oil; yield: 87%, MS: 425 (MH⁺).

[0490] A solution of 400 mg (0.86 mmol)(2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine in 15 ml CH₂Cl₂with 0.3 ml (2.2 mmol) trimethylsilylisocyanate and a catalytic amountof DMAP was stirred over night. The reaction was extracted with aqueous10% KHSO₄/EtOAc (3×) and the organic phase was dried over Na₂SO₄.Crystallization (CH₂Cl₂/MeOH/Et₂O) gave 205 mg (47%)(2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-carboxylic acidamide, MS: 509 (MH⁺).

[0491] Trityl deprotection (Method 3)(2S,4R)-2-benzyloxymethyl-4-mercapto-pyrrolidine-1-carboxylic acidamide, MS: 267 (MH⁺).

Example 14.g Ether, Amides (Table 9 and Table 10)

[0492] General procedure Method A: 2 equivalents of an acid (0.996 mmol)in 1.7 ml THF at −10° C. were treated with 75 μl (0.48 mmol) diisopropylcarbodiimide and a catalytic amount of DMAP and warmed up to roomtemperature over night. 150 mg (0.32 mmol)(2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine were then addedand after 5 h filtered and purified by prep HPLC (RP18, CH₃CN/H₂O 80:20to 95:5).

[0493] General procedure Method B: A solution of 0.25 mmol(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidineand 0.375 mmol acid in 1 ml dioxane was treated with 0.375 mmol EDCI in1 ml CH₂Cl₂ and a catalytic amound of DMAP and stirred at roomtemperature over night. After evaporation and purification by prep HPLC(RP18, CH₃CN/H₂O 80:20 to 95:5) the amide was received.

[0494] Trityl deprotection following Method 4 gave the free thiol.

[0495] By the reaction of(2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine with the secondeduct metioned in table 9 the compounds mentioned in table 9 wereobtained.

[0496] By the reaction of(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanylpyrrolidinewith the second educt metioned in table 10 the compounds mentioned intable 10 were obtained. TABLE 9 Name 2. Educt MS 1(2S,4R)-1-(2-Benzyloxymethyl-4-mercapto- ISOBUTYRIC ACID M+H+ 294pyrrolidin-1-yl)-2-methyl-propan-1-one 2(2S,4R)-1-(2-Benzyloxymethyl-4-mercapto- ACETIC ACID M+H+ 266pyrrolidin-1-yl)-ethanone 3((2S,4R)-2-Benzyloxymethyl-4-mercapto-pyrrolidin- BENZOIC ACID M+H+ 3281-yl)-phenyl-methanone 4((2S,4R)-2-Benzyloxymethyl-4-mercapto-pyrrolidin- P-ANISIC ACID M+H+ 3581-yl)-(4-methoxy-phenyl)-methanone 5((2S,4R)-2-Benzyloxymethyl-4-mercapto-pyrrolidin- 3-BROMOBENZOIC ACIDM+H+, 1Br 406 1-yl)-(3-bromo-phenyl)-methanone 6(2S,4R)-(2-Benzyloxymethyl-4-mercapto-pyrrolidin- 2,4-DIFLUOROBENZOICACID M+H+ 364 1-yl)-(2,4-difluoro-phenyl)-methanone 7(2S,4R)-(2-Benzyloxymethyl-4-mercapto-pyrrolidin- 4-BIPHENYLCARBOXYLICACID M+H+ 404 1-yl)-biphenyl-4-yl-methanone 8(2S,4R)-(2-Benzyloxymethyl-4-mercapto-pyrrolidin- 4-BROMOBENZOIC ACIDM+H+, 1Br 406 1-yl)-(4-bromo-phenyl)-methanone 9(2S,4R)-(2-Benzyloxymethyl-4-mercapto-pyrrolidin- 2,4-DIMETHOXYBENZOICACID M+H+ 388 1-yl)-(2,4-dimethoxy-phenyl)-methanone 10(2S,4R)-1-(2-Benzyloxymethyl-4-mercapto- 4-BIPHENYLACETIC ACID M+H+ 418pyrrolidin-1-yl)-2-biphenyl-4-yl-ethanone

[0497] TABLE 10 Name 2. Educt Method MS 1.(2S,4R)-[4-Mercapto-2-(2,4,5-trifluoro- BENZOIC ACID B M+H+ 382benzyloxymethyl)-pyrrolidin-1-yl]-phenyl- methanone 2.(2S,4R)-1-[4-Mercapto-2-(2,4,5-trifluoro- PHENYLACETIC ACID B M+H+ 396benzyloxymethyl)-pyrrolidin-1-yl]-2-phenyl- ethanone 3.(2S,4R)-Biphenyl-4-yl-[4-mercapto-2-(2,4,5- 4-BIPHENYL-CARBOXYLIC ACID BM+H+ 458 trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]- methanone 4.(2S,4R)-2-Biphenyl-4-yl-1-[4-mercapto-2-(2,4,5- 4-BIPHENYLACETIC ACID BM+H+ 472 trifluoro-benzyloxymethyl)-pyrrolidin-1- 5.(2S,4R)-2-(1H-Indol-3-yl)-1-[4-mercapto-2-(2,4,5- INDOLE-3-ACETIC ACID BM+H+ 435 trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]-ethanone 6.(2S,4R)-(1H-Indol-2-yl)-[4-mercapto-2-(2,4,5- INDOLE-2-CARBOXYLIC ACID BM+H+ 421 trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]- methanone 7.(2S,4R)-(1H-Indol-3-yl)-[4-mercapto-2-(2,4,5- INDOLE-3-CARBOXYLIC ACID BM+H+ 421 trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]- methanone 8.(2S,4R)-(1H-Indol-5-yl)-[4-mercapto-2-(2,4,5- INDOLE-5-CARBOXYLIC ACID BM+H+ 421 trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]- methanone 9.(2S,4R)-(1H-Indol-6-yl)-[4-mercapto-2-(2,4,5- INDOLE-6-CARBOXYLIC ACID BM+H+ 421 trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]- methanone 10.(2S,4R)-(1H-Indol-7-yl)-[4-mercapto-2-(2,4,5- INDOLE-7-CARBOXYLIC ACID BM+H+ 421 trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]- methanone 11.Mixture of (R)- and (S)-N-[1-(1H-Indol-3-ylmethyl)-N-ACETYL-DL-TRYPHOPHAN B M+H+ 506 2-[(2S,4R)-4-mercapto-2-(2,4,5-trifl12. (2S,4R)-3-(1H-Indol-3-yl)-1-[4-mercapto-2-(2,4,5- 3-INDOLEPROPIONICACID B M+H+ 449 trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]-propan-1-one 13. (2S,4R)-4-(1H-Indol-3-yl)-1-[4-mercapto-2-(2,4,5-3-INDOLEBUTYRIC ACID B M+H+ 463trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]-buthan-1- one 14.(2S,4R)-3-Indol-1-yl-1-[4-mercapto-2-(2,4,5- BETA-N-INDOLEPROPIONIC BM+H+ 449 trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]-propan- ACID 1-one15. (1S)-N-[1-[(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- N-ACETYL-L-LEUCINEB M+H+ 433 benzyloxymethyl)-pyrrolidine-1-carbonyl]-3-methyl-butyl}-acetamide 16. (2S,4R)-1-[4-Mercapto-2-(2,4,5-trifluoro-3-methyl-1-butanoic acid B M+H+ 362benzyloxymethyl)-pyrrolidin-1-yl]-3-methyl-butan-1- one 17.(25,4R)-1-[4-Mercapto-2-(2,4,5-trifluoro- 4-methyl-1-pentanoic acid BM+H+ 376 benzyloxymethyl)-pyrrolidin-1-yl]-4-methyl-pentan- 1-one 18.(2S,4R)-1-[4-Mercapto-2-(2,4,5-trifluoro- 1-butanoic acid B M+H+ 348benzyloxymethyl)-pyrrolidin-1-yl]-butan-1-one 19.(2S,4R)-1-[4-Mercapto-2-(2,4,5-trifluoro- 5-methyl-1-hexanoic acid BM+H+ 390 benzyloxymethyl)-pyrrolidin-1-yl]-5-methyl-hexan- 1-one 20.(2S,4R)-1-[4-Mercapto-2-(2,4,5-trifluoro- 1-hexanoic acid B M+H+ 376benzyloxymethyl)-pyrrolidin-1-yl]-hexan-1-one 21.(2-Hydroxy-phenyl)-[(2S,4R)-4-mercapto-2-(2,4,5- SALICYLIC ACID B M+H+398 trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]- methanone 22.1-[(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro- ACETIC ACID B M+H+ 320benzyloxymethyl)-pyrrolidin-1-yl]-ethanone

Example 14.h Ether, Sulfamides

[0498] Sulfamides, Method A: SO₂NH₂: A solution of 567 mg (1.09 mmol)(2S,4R)-2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine,302 mg (1.09 mmol) sulfamic acid 2,4,6-trichloro-phenyl ester[Hedayatullah, M. & Hugueny, J. Phosphorus, Sulfur Silicon Relat. Elem.(1991), 61(1-2), 19-25.] and 0.15 ml triethylamine in 2 ml CH₂Cl₂ washeated for 1 h at reflux, evaporated and purified by flash columnchromatography on silica gel with hexane/EtOAc (9:1 to 1:1) to give 286mg (44%)(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid amide. [Hedayatullah, M. & Hugueny, J. Phosphorus Sulfur (1985),25(1), 33-8.] MS: 621 (M+Na⁺).

[0499] Trityl deprotection (Method 3)(2S,4R)-4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid amide, MS: 355 (M−H)⁻.

[0500] In analogy:(2S,4R)-2-Benzyloxymethyl-4-tritylsulfanyl-pyrrolidine, gave(2S,4R)-2-benzyloxymethyl-4-mercapto-pyrrolidine-1-sulfonic acid amide,MS: 303 (M+H).

[0501] Sulfamide, Method B: SO₂NHR (via NSO₂Cl) Following a proceduredescribed in U.S. Pat. No. 4,868,308: 2.12 ml (21.5 mmol) Alpha-picolineand 0.19 ml (2.8 mmol) chloro sulfonic acid were added at −10° C. to 30ml 1,2-dimethoxyethane, warmed up to 10° C. and treated with 431 mg(0.93 mmol) of (2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine.The reaction was stirred at room temperature over night, treated with0.32 ml (3.5 mmol) POCl₃ and after 4 h at room temperature with 5 ml8.03 M MeNH₂ in EtOH. The reaction was stirred over night and extractedwith aqueous 10% KHSO₄/EtOAc (3×), the organic phases were washed with10% NaCl. The crude product was crystallized from CH₂Cl₂/Et₂O at −20° C.to give 147 mg (28%) of(2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-sulfonic acidmethylamide, mp 140-142° C., MS: 581 (M+Na⁺).

[0502] Trityl deprotection (Method 3) gave(2S,4R)-2-benzyloxymethyl-4-mercapto-pyrrolidine-1-sulfonic acidmethylamide, MS: 315 (M−H)⁻.

[0503] Sulfamide, Method C:

[0504] Preparation of Sulfamoyl Chlorides

[0505] Method C1:

[0506] The amine (3 eq.) was dissolved in CH₂Cl₂ (1 ml/mmol) and placedin an ice bath. A solution of chlorosulfonic acid (1 eq.) in CH₂Cl₂ (0.5ml/mmol) was added slowly (30 min). The reaction mixture was stirred at0° C. for a further 30 min. Afterward, the ice bath was removed and thestirring was continued for 1 h at room temperature. The precipitate wascollected by filtration and dried under high vacuum. This salt wassuspended in toluene (1 ml/mmol amine) and PCd₅ (1 eq) was added. Themixture was stirred at 75° C. for 2 h, cooled to room temperature andfiltered. The solid residue was washed with toluene. The filtrate wasevaporated and dried under high vacuum. The crude sulfamoyl chloride wasused in the next step without further purification.

[0507] Benzylsulfamoyl chloride (75%)

[0508] Phenylsulfamoyl chloride (72%)

[0509] Butylsulfamoyl chloride (45%)

[0510] Phenethylsulfamoyl chloride (52%)

[0511] 2-Phenoxyethylsulfamoyl chloride (20%)

[0512] Cyclohexylmethylsulfamoyl chloride (74%)

[0513] Cyclopropylmethylsulfamoyl chloride (100%)

[0514] Cyclopropylsulfamoyl chloride (82%)

[0515] 2,2,2-Trifluoroethylsulfamoyl chloride (74%)

[0516] 4-Fluoro-benzylsulfamoyl chloride (39%)

[0517] Method C2:

[0518] The amine hydrochloride (1 eq.) was dissolved in CH₃CN and placedin an ice bath. Sulfuryl chloride (3 eq.) was added slowly (20 min). Thereaction mixture was stirred at room temperature for 15 min and at 65°C. for 20 h. The solvent was evaporated and the residue was dried underhigh vacuum. The crude sulfamoyl chloride was used in the next stepwithout further purification.

[0519] 3-Chlorosulfonylamino-propionic acid ethyl ester

[0520] 4-(Chlorosulfonylamino-methyl)-benzoic acid methyl ester

[0521] Preparation of sulfamides:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine(1 eq) was dissolved in CH₂Cl₂ (2 ml/mmol) and placed in an ice bath.Diisopropylethyl amine (1.4 eq) was added and stirred for 5 min. Asolution of the crude sulfamoyl chloride (1.4 eq) in CH₂Cl₂ (1 ml/mmol)was added. The ice bath was removed and the stirring was continued atRTovernight. A aqueous saturated solution of KHSO₄ was added andextracted with EtOAc. The organic phase was washed with water, driedover Na₂SO₄ and evaporated. The product was purified by chromatography(SiO₂, hexane=>hexane/EtOAc 70:30)

[0522] Benzyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid benzylamide; yield: 75%, MS: 687 (M−H)⁻;

[0523] Phenyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid phenylamide; yield: 72%;

[0524] Butyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid butylamide; yield: 45%, MS: 653 (M−H)⁻;

[0525] Phenethyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid phenethylamide; yield: 52%;

[0526] Phenoxyethyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid (2-phenoxy-ethyl)-amide; yield: 20%, MS: 717 (M−H)⁻;

[0527] Cyclohexylmethyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid cyclohexylmethyl-amide; yield: 74%, MS: 694 (M−H)⁻;

[0528] Cyclopropylmethyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid cyclopropylmethyl-amide; yield: quant., MS: 651 (M−H)⁻;

[0529] Cyclopropyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid cyclopropyl-amide; yield: 82%, MS: 637 (M−H)⁻;

[0530] 2,2,2-Trifluoro-ethyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid (2,2,2-trifluoro-ethyl)-amide; yield: 78%, MS: 679 (M−H)⁻;

[0531] 4-Fluoro-benzyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid 4-fluoro-benzylamide; yield: 39%, MS: 705 (M−H)⁻;

[0532] Acetic acid ethyl ester:(2S,4R)-[2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonylamino]-aceticacid ethyl ester; yield: 85%, MS: 682 (M−H)⁻;

[0533] 4-Methoxycarbonyl-benzyl:(2S,4R)-[4-{[2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonylamino]-methyl}-benzoicacid methyl ester; yield: 63%;

[0534] Dimethyl: (2S,4R)-2-Benzyloxymethyl-4-tritylsulfanyl-pyrrolidineand dimethylsulphamoyl chloride gave(2S,4R)-2-Benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-sulfonic aciddimethylamide, MS: 573 (MH⁺).

Example 14.i Ether, Alkylation of Sulfamides

[0535] A solution of the sulfamide in DMF (20 ml/mmol) was placed in anice bath. NaH (55% in mineral oil, 1.2 eq.) was added and stirred for 30min. The alkylating agent (MeI or t-butylbromoacetate, 1.2 eq.) wasadded and stirred overnight at room temperature. A aqueous saturatedsolution of NH₄Cl was added and the mixture was extracted withdichloromethane. The organic phase was dried (Na₂SO₄), filtered andevaporated. The product was purified by chromatography (SiO₂,EtOAc/hexane 95:5=>hexane/EtOAc 70:30.

[0536] Benzyl-methyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid benzyl-methyl-amide; yield: 36%, MS: 703 (M+H)⁺;

[0537] Methyl-phenyl:(2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid methyl-phenyl-amide; yield: 84%;

[0538] Benzyl-acetic acid t-butyl ester:{Benzyl-[2-(2,4,5-trifluoro-benzyloxymethyl)-4-tritylsulfahyl-pyrrolidine-1-sulfonyl]-amino}-aceticacid-tert-butyl ester; yield: 77%;

[0539] Deprotection (Method 3): Triethylsilane (10 eq.) was added to asolution of the trityl-protected thiol (1 eq.) in trifluoroacetic acid(200 eq.) at 0° C. The reaction mixture was stirred for 30 min at 0° C.The solvent was evaporated under vacuum at 0° C. The product waspurified by chromatography (SiO₂, CH₂Cl₂=>CH₂Cl₂/MeOH 9:1).

[0540] Benzyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid benzylamide; colorless oil; yield: 85%, MS: 445 (M−H)⁻;

[0541] Phenyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid phenylamide; yellowish oil; yield: quant., MS: 431 (M−H)⁻;

[0542] Butyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid butylamide; colorless solid; yield: 69%, MS: 411 (M−H)⁻;

[0543] Phenethyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid phenethylamide; colorless oil; yield: 53%, MS: 459 (M−H)⁻;

[0544] Phenoxyethyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid (2-phenoxy-ethyl)-amide; colorless oil; yield: quant., MS: 475(M−H)⁻;

[0545] Cyclohexylmethyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid cyclohexylmethyl-amide; colorless solid; yield: 87%, MS: 451(M−H)⁻;

[0546] Cyclopropylmethyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid cyclopropylmethyl-amide; colorless solid; yield: 94%, MS: 409(M−H)⁻;

[0547] Cyclopropyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid cyclopropyl-amide; colorless oil; yield: 75%, MS: 395 (M-H)—;

[0548] 2,2,2-Trifluoro-ethyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid (2,2,2-trifluoro-ethyl)-amide; colorless oil; yield: 88%, MS: 437(M−H)⁻;

[0549] 4-Fluoro-benzyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid 4-fluoro-benzylamide; colorless oil; yield: 86%, MS: 463 (M−H)⁻;

[0550] Benzyl-methyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid benzyl-methyl-amide; colorless oil; yield: 87%, MS: 425 (M+H)⁺;

[0551] Methyl-phenyl:(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid methyl-phenyl-amide; light green oil; yield: 86%, MS: 447 (M+H)⁺;

[0552] Benzyl-acetic acid:{Benzyl-[4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonyl]-amino}-aceticacid; colorless oil; yield: 88%, MS: 503 (M−H)⁻;

[0553] Acetic acid ethyl ester:(2S,4R)-[4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonylamino]-aceticacid ethyl ester; colorless oil; yield: 96%, MS: 443 (M+H)⁺;

[0554] 4-Methoxycarbonyl-benzyl:(2S,4R)-4-{[4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonylamino]-methyl}-benzoicacid methyl ester; colorless oil; yield: 70%, MS: 503 (M−H)⁻;

[0555] Dimethyl:(2S,4R)-2-Benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-sulfonic aciddimethylamide gave, MS: 331 (MH⁺);

[0556](2S,4R)-2-(2,4,5-Trifluoro-benzyloxymethyl)-4-tritylsulfanyl-pyrrolidinegave over two steps(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid dimethylamide, MS: 385 (MH⁺).

Example 14.k Ether, Sulfonic Acid

[0557] A solution of 2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine(0.435 g) in dichloromethane (30.0 ml) was treated with 2-picoline (2.11ml) and chlorosulphonic acid (0.186 ml). The reaction mixture wasstirred for 5 h at room temperature and evaporated to dryness. Theresidue was quenched with ice/water and extracted with EtOAc. Theaqueous layer was saturated with sodium chloride and acidified with 1molar HCl to pH 3.4 and extracted again with EtOAc. The organic phasewas washed with brine, dried over magnesium sulphate and concentrated toobtain (2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-sulfonicacid (0.26 g) as an oil, MS: 544 (M−H)⁻.

[0558] To a solution of(2S,4R)-2-benzyloxymethyl-4-tritylsulfanyl-pyrrolidine-1-sulfonic acid(0.24 g) in dichloromethane (2.0 ml) was added triethylsilane (0.51 g)and trifluoroacetic acid (8.0 ml) at −10° C. The reaction mixture wasstirred at −5° C. for 0.5 h and concentrated without heating. Theresidue was treated with water, acidified to pH 3-4 with HCl, andextracted with EtOAc. The organic phase was washed with brine, driedover magnesium sulphate and evaporated to dryness without heating. Theresidue was dissolved in a solution of water (3 ml) and sodium acetate(0.165 g) and chromatographed on MCI using water/methanol 1:1 as eluentto obtain 2-benzyloxymethyl-4-mercapto-pyrrolidine-1-sulfonic acidsodium salt (0.105 g) as a colourless powder after lyophillisation, MS:302 (M−H)⁻.

Example 15 Synthesis of C-Analogues

[0559](2R,4R)-4-(4-Methoxy-benzylsulfanyl)-2-(2-methoxycarbonyl-ethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester gave after hydrolysis (General method forhydrolysis of an ester) and Weinreb-amide formation (General method forEDCI-coupling)(2R,4R)-4-(4-methoxy-benzylsulfanyl)-2-[2-(methoxy-methyl-carbamoyl)-ethyl]-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 439 (MH⁺).

[0560] A solution of 200 mg (0.456 mmol)(2R,4R)-4-(4-Methoxy-benzylsulfanyl)-2-[2-(methoxy-methyl-carbamoyl)-ethyl]-pyrrolidine-1-carboxylicacid tert-butyl ester in 3 ml THF was treated at 0° C. with 1.14 ml(1.14 mmol, IM THF solution) of a 4-fluorophenyl-magnesium bromidesolution and after 10 min warmed up to room temperature. The reactionwas partitioned between aqueous aqueous 10% KHSO₄/t-butyl methyl ether(3×). The organic phases were washed with aqueous 10% NaHCO₃ andsaturated NaCl solution, dried over MgSO₄ and evaporated to give 144 mg(68%) of(2R,4R)-2-[3-(4-fluoro-phenyl)-3-oxo-propyl]-4-(4-methoxy-benzylsulfanyt)-pyrrolidine-1-carboxylicacid tert-butyl ester, MS: 474 (MH⁺).

[0561] A solution of 0.539 g (1.14 mmol)(2R,4R)-2-[3-(4-Fluoro-phenyl)-3-oxo-propyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid tert-butyl ester in 10 ml CH₂Cl₂ was treated at 0° C. with 0.43 mlTFA. After 30 min the reaction was warmed up to room temperature (2 h)and evaporated to give(2R,4R)-1-(4-fluoro-phenyl)-3-[4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-propan-1-one;compound with trifluoro-acetic acid, MS: 374 (MH⁺).

[0562] The crude mixture was dissolved in 20 ml CH₂Cl₂ and treated with0.68 ml (6.2 mmol) N-methylmorpholine and 0.24 ml (1.86 mmol) n-butylchloroformate. The reaction was stirred over night and partitionedbetween aqueous aqueous 10% KHSO₄/CH₂Cl₂ (3×). The organic phases werewashed with aqueous 10% NaHCO₃ and saturated NaCl solution, dried overMgSO₄ and evaporated to give 72 mg (12%)(2R,4R)-2-[3-(4-fluoro-phenyl)-3-oxo-propyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid butyl ester, MS: 474 (MH⁺) and 36 mg (6%)(2R,4R)-1-(4-fluoro-phenyl)-3-[4-(4-methoxy-benzylsulfanyl)-1-trifluoroacetyl-pyrrolidin-2-yl]-propan-1-one,MS: 470 (MH⁺).

[0563] In analogy:(2R,4R)-4-(4-Methoxy-benzylsulfanyl)-2-[2-(methoxy-methyl-carbamoyl)-ethyl]-pyrrolidine-1-carboxylicacid tert-butyl ester was:

[0564] 1. TFA deprotected (see above) to give(2R,4R)-N-methoxy-3-[4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-N-methyl-propionamide;compound with trifluoro-acetic acid, MS: 339 (MH⁺);

[0565] 2. Sulfonylated (see above) with methanesulfonyl chloride to give(2R,4R)-3-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-N-methoxy-N-methyl-propionamide,MS: 417 (MH⁺) and with 2-naphthylsulfonyl chloride(2R,4R)-N-methoxy-3-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-N-methyl-propionamide,MS: 529 (MH⁺);

[0566] 3. Reacted with a 1M THF solution of 4-fluorophenylmagnesiumbromide (see above) to give(2R,4R)-1-(4-fluoro-phenyl)-3-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-propan-1-one,MS: 452 (MH⁺) and(2R,4R)-1-(4-fluoro-phenyl)-3-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-propan-1-one,MS: 564 (MH⁺).

[0567] A solution of 72 mg (0.152 mmol)(2R,4R)-2-[3-(4-fluoro-phenyl)-3-oxo-propyl]-4-(4-methoxy-benzylsulfanyl)-pyrrolidine-1-carboxylicacid butyl ester and 0.12 (1.4 mmol) triethylsilane in 2.7 ml TFA washeated for 18 h at 80° C. Evaporation followed by flash chromatographyon silica gel (EtOAc/hexane 7:3) gave 8 mg (15%)(2R,4R)-2-[3-(4-fluoro-phenyl)-propyl]-4-mercapto-pyrrolidine-1-carboxylicacid butyl ester, MS: 340 (MH⁺).

[0568] In analogy:(2R,4R)-1-(4-fluoro-phenyl)-3-[4-(4-methoxy-benzylsulfanyl)-1-trifluoroacetyl-pyrrolidin-2-yl]-propan-1-onegave(2R,4R)-2,2,2-trifluoro-1-{2-[3-(4-fluoro-phenyl)-propyl]-4-mercapto-pyrrolidin-1-yl}-ethanone,MS: 336 (MH⁺).

[0569](2R,4R)-1-(4-Fluoro-phenyl)-3-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-pyrrolidin-2-yl]-propan-1-onegave(2R,4R)-5-[3-(4-fluoro-phenyl)-propyl]-1-methanesulfonyl-pyrrolidine-3-thiol,MS: 318 (MH⁺).

[0570](2R,4R)-1-(4-fluoro-phenyl)-3-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-propan-1-onegave(2R,4R)-5-[3-(4-fluoro-phenyl)-propyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiol,MS: 336 (MH⁺).

Example 16 5-Ring Ether Synthesis with the Final Introduction of Thiol

[0571] Cis-Compound:

[0572] Tert-Butyletherification: To a solution of(2S,4R)-4-hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid benzyl ester (14.8 g) in dichloromethane (140 ml) were added borontrifluoride ethyl etherate (3 ml) and isobutylene (cooled and liquefiedat −30° C., 170 ml) at −30° C. The turbid reaction mixture was stirredat −20° C. for 2 h, poured onto a saturated sodium bicarbonate solution,and extracted with dichloromethane. The organic phases were washed withwater, dried over magnesium sulphate and concentrated. The residue waschromatographed on silica gel using EtOAc/hexane 1:4 and 1:2 as eluentsto obtain(2S,4R)-4-tert-butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid benzyl ester (16.4 g) as a glassy syrup, MS: 467 (M).

[0573] In analogy (6-ring):(2RS,5RS)-5-Hydroxymethyl-1-methanesulfonyl-piperidine-2-carboxylic acidmethyl ester (3.85 g) gave(2RS,5RS)-5-tert-butoxymethyl-1-methanesulfonyl-piperidine-2-carboxylicacid methyl ester (4.40 g) as a syrup, MS: 250 (M-57).

[0574] LAH reduction: To a slurry of lithium aluminium hydride (0.72 g)in Et₂O (120 ml) was added a solution of(2S,4R)-4-tert-butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylicacid benzyl ester (9.0 g) in Et₂O (80 ml) dropwise at −15° C. within 0.5h. The suspension was stirred for 2 h at the same temperature, then asaturated solution of potassium-sodium tartrate (10 ml) was addeddropwise. The slurry was filtered through a pad of filter aid and waswashed with Et₂O. The combined filtrates were washed with brine, driedover magnesium sulphate and concentrated. The residue was crystallizedfrom acetone/Et₂O/hexane to obtain(2S,4R)-[4-tert-butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanol(6.1 g) as a colorless solid, mp 124-125° C.; MS 363 (M).

[0575] In analogy (6-ring):(2RS,5RS)-5-tert-Butoxymethyl-1-methanesulfonyl-piperidine-2-carboxylicacid methyl ester (4.20 g) gave(2RS,5RS)-(5-tert-butoxymethyl-1-methanesulfonyl-piperidin-2-yl)-methanol(3.67 g) as a colourless solid: mp 100-102° C., MS: 280 (MH⁺).

[0576] R²-ether formation: To a slurry of sodium hydride (60% in mineraloil, 2.75 g) in DMSO (100 ml) were added(2S,4R)-[4-tert-butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanol(11.2 g) in portions within 0.5 h and benzyl bromide (7.2 ml) dropwisewithin 0.5 h at 20° C. The reaction mixture was stirred at roomtemperature for 1.5 h, poured onto ice/water and extracted with EtOAc.The organic phases were washed with water and brine, dried overmagnesium sulphate and concentrated. The residue was crystallized fromacetone/Et₂O/hexane to obtain(2S,4R)-2-benzyloxymethyl-4-tert-butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidine(10.05 g) as a colorless solid, mp 101-103° C., MS: 454 (MH⁺).

[0577] In analogy:(2S,4R)-[4-tert-Butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanol(2.18 g) and 3-bromomethylbenzoic acid methyl ester gave(3S,5R)-3-[4-tert-butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (2.08 g) as a colourless solid: mp 126-127° C.; MS:480 (M-OCH₃).

[0578](2S,4R)-[4-tert-Butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanol(7.26 g) and cinnamyl bromide gave after chromatography on silica gelusing EtOAc/hexane 1:3 as eluent(E)-(2S,4R)-4-tert-butoxy-1-(naphthalene-2-sulfonyl)-2-(3-phenyl-allyloxymethyl)-pyrrolidine(7.2 g) as a solid, MS: 480 (MH⁺).

[0579] Hydrogenation: A solution of(E)-(2S,4R)-4-tert-butoxy-1-(naphthalene-2-sulfonyl)-2-(3-phenyl-allyloxymethyl)-pyrrolidine(2.3 g) in ethanol/dioxane 1:2 (75 ml) was hydrogenated in the presenceof 10% palladium on charcoal (0.50 g) at 1.1 bar and room temperaturefor 4 h. The reaction mixture was filtered over a pad of celite andwashed with ethanol. The filtrate was concentrated, and the residue waschromatographed on silica gel using EtOAc/hexane 1:4 as eluent to obtain(2S,4R)-4-tert-butoxy-1-(naphthalene-2-sulfonyl)-2-(3-phenyl-propoxymethyl)-pyrrolidine(2.16 g) as a gum, MS: 482 (MH⁺).

[0580] Mitsunobu reaction: To a solution of(2S,4R)-[4-tert-butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanol(1.81 g) in THF (15 ml) were added phenol (0.495 g) andtriphenylphosphine (1.38 g) in one portion at room temperature anddiisopropyl azodicarboxylate (1.0 ml) dropwise in 2 minutes. Thereaction mixture was stirred over night at room temperature andconcentrated. The residue was treated with water and extracted withEtOAc. The organic phase was washed with 1N sodium hydroxide, saturatedsodium bicarbonate solution and brine, dried over magnesium sulphate andconcentrated. The residue was chromatographed on silica gel usingEtOAc/hexane 1:3 as eluent to obtain(3S,5R)-4-tert-butoxy-1-(naphthalene-2-sulfonyl)-2-phenoxymethyl-pyrrolidineas a colourless powder, MS: 439 (M).

[0581] (6-ring): To a solution of(2RS,5RS)-(5-tert-butoxymethyl-1-methanesulfonyl-piperidin-2-yl)-methanol(2.80 g) in dichloromethane (20 ml) and cyclohexane (30 ml) was addedbenzyl 2,2,2-trichloroacetimidate (3.03 g) andtrifluoromethanesulphoriic acid (0.2 ml). The reaction mixture wasstirred 1 h at room temperature, poured onto a saturated sodiumbicarbonate solution and extracted with EtOAc. The organic phase waswashed with brine, dried over magnesium sulphate and concentrated. Theresidue was chromatographed on silica gel using EtOAc/hexane 1:3 and 1:2as eluents to obtain(2RS,5RS)-2-benzyloxymethyl-5-tert-butoxymethyl-1-methanesulfonyl-piperidine(3,6 g) as a syrup, MS: 369 (M⁺).

[0582] Trifluoroacetic acid (100 ml) was cooled to 0° C., then(2S,4R)-2-benzyloxymethyl-4-tert-butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidine(7.0 g) was added in one portion. The reaction mixture was stirred for 3h at the same temperature and then concentrated without heating undervacuum. The residue crystallized from Et2O/hexane to obtain(3R,5S)-5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-ol(5.07 g) as a colorless solid, mp 124-126° C., MS: 398 (MH⁺).

[0583] In analogy:(3S,5R)-3-[4-tert-Butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (2.00 g) gave(3S,5R)-3-[4-hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (0.98 g) as a colourless powder: MS: 456 (MH⁺).

[0584](2S,4R)-4-tert-Butoxy-1-(naphthalene-2-sulfonyl)-2-(3-phenyl-propoxymethyl)-pyrrolidinegave(3R,5S)-1-(naphthalene-2-sulfonyl)-5-(3-phenyl-propoxymethyl)-pyrrolidin-3-ol(1.36 g) as a foam: MS: 426 (MH⁺).

[0585](3S,5R)-4-tert-Butoxy-1-(naphthalene-2-sulfonyl)-2-phenoxymethyl-pyrrolidine(1.5 g) gave(3S,5R)-1-(naphthalene-2-sulfonyl)-5-phenoxymethyl-pyrrolidin-3-ol (0.82g) as a white powder: MS: 384 (MH⁺).

[0586] (6-ring)(2RS,5RS)-2-Benzyloxymethyl-5-tert-butoxymethyl-1-methanesulfonyl-piperidine(3.4 g) gave(3RS,6RS)-(6-benzyloxymethyl-1-methanesulfonyl-piperidin-3-yl)-methanol(1.75 g) as a colourless syrup, MS: 313 (M⁺).

[0587] To a solution of triphenylphosphine (2.92 g) in tetrahydrofuran(30 ml) was added diisopropylazodicarboxylate (2.20 ml) within 5 minutesat 0° C. The solution was stirred for 0.5 h at 0° C., then a solution of(3R,5S)-5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-ol(2.2 g) and thioacetic acid (0.81 ml) in tetrahydrofurane (10 ml) wereadded to the suspension within 0.5 h at 0° C. Stirring was continued for1 h at 0° C. and 1 h at room temperature. The reaction mixture wasconcentrated, and the residue was chromatographed on silica gel usingEtOAc/hexane 1:4 and 1:3 as eluents to obtain (3S,5S)-thioacetic acidS-[5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yl] ester(2.1 g) as a syrup, MS: 456 (MH⁺).

[0588] In analogy:(3S,5R)-3-[4-Hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (0.78 g) was reacted as described above to obtain(2S,4S)-3-[4-acetylsulfanyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (0.34 g) as a thick syrup, MS: 514 (MH⁺).

[0589](3R,5S)-1-(Naphthalene-2-sulfonyl)-5-(3-phenyl-propoxymethyl)-pyrrolidin-3-ol(0.48 g) gave thioacetic acid(3S,5S)-S-[1-(naphthalene-2-sulfonyl)-5-(3-phenyl-propoxymethyl)-pyrrolidin-3-yl]ester(0.41 g) as a syrup, MS: 484 (MH⁺).(3S,5R)-1-(naphthalene-2-sulfonyl)-5-phenoxymethyl-pyrrolidin-3-ol (0.54g) gave (3S,5S)-thioacetic acidS-[-(naphthalene-2-sulfonyl)-5-phenoxymethyl-pyrrolidin-3-yl]ester (0.54g) as a glassy syrup, MS: 442 (MH⁺).

[0590] (6-ring)(3RS,6RS)-(6-Benzyloxymethyl-1-methanesulfonyl-piperidin-3-yl)-methanol(0.94 g) gave thioacetic acid(3RS,6RS)—S-(6-benzyloxymethyl-1-methanesulfonyl-piperidin-3-ylmethyl)ester as a colorless syrup, MS: 371 (M⁺).

[0591] S-Acetyl deprotection: To a solution of (3S,5S)-thioacetic acidS-[5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yl] ester(1.2 g) in methanol (17 ml) was added sodium methanolate (28%-solutionin methanol, 0.55 ml) at 0° C. The reaction mixture was stirred at 0° C.for 1.5 h, and acetic acid (0.17 ml) was added. The reaction mixture wasconcentrated, and the residue was extracted with EtOAc. The organicphases were washed with water, dried over magnesium sulphate andconcentrated. The residue was chromatographed on silica gel usingEtOAc/hexane 1:3 and 1:2 as eluents to obtain(3S,5S)-5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiol(0.59 g) as a slightly coloured syrup, MS: 414 (MH⁺).

[0592] In analogy:(2S,4S)-3-[4-Acetylsulfanyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (0.30 g) gave(2S,4S)-3-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (0.21 g) as a colourless amorphous powder, MS: 440(M-OCH3).

[0593] Thioacetic acid(3S,5S)—S-[1-(naphthalene-2-sulfonyl)-5-(3-phenyl-propoxymethyl)-pyrrolidin-3-yl]ester (0.33 g) gave(3S,5S)-1-(naphthalene-2-sulfonyl)-5-(3-phenyl-propoxymethyl)-pyrrolidine-3-thiol(0.23 g) as a syrup, MS: 407 (M−H₂S).

[0594] (3S,5S)-Thioacetic acidS-[1-(naphthalene-2-sulfonyl)-5-phenoxymethyl-pyrrolidin-3-yl] ester(0.5 g) gave(3S,5S)-1-(naphthalene-2-sulfonyl)-5-phenoxymethyl-pyrrolidine-3-thiol(0.27 g) as a colourless powder, MS: 399 (M).

[0595] 6-ring: Thioacetic acid(3RS,6RS)—S-(6-benzyloxymethyl-1-methanesulfonyl-piperidin-3-ylmethyl)ester (0.78 g) gave(3RS,6RS)-(6-benzyloxymethyl-1-methanesulfonyl-piperidin-3-yl)-methanethiol(0.52 g) as a syrup, MS: 329 (M⁺).

[0596] To solution of(2S,4S)-3-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (0.48 g) in methanol (14 ml) was added a 0.1 molarsodium carbonate solution (25 ml). The reaction mixture was refluxed for5 h and concentrated. The residue was treated with 1 eq 1N HCl, waterand extracted with EtOAc.

[0597] The organic phase was washed with brine, dried over magnesiumsulphate and concentrated. The residue was chromatographed on silica gelusing EtOAc/methanol/water 93:5:2 as eluent to obtain(2S,4S)-3-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid (0.34 g) as a colourless thick syrup, MS: 458 (MH⁺).

Example 17 5-Ring Ether Synthesis with the Final Introduction of Thiol

[0598] Trans Compound:

[0599] To a suspension of methanesulphonic acid (0.96 g) in toluene (30ml) was added triethylamine (1.40 ml) and triphenylphosphine (2.72 g) at0-5° C. The suspension was stirred for 5 minutes, and(3R,5S)-5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-ol(3.46 g) dissolved in toluene (20 ml) was added dropwise in 5 minutes,followed by diisipropyl azodicarboxylate (2.0 ml). The reaction mixturewas stirred for 3 h at 85° C., poured onto ice/water and extracted withethy acetate. The organic phase was washed with 10% KHSO₄— and NaClsolutions, dried over magnesium sulphate and concentrated. The residuewas chromatographed on silica gel using EtOAc/hexane 1:2 and 1:1 aseluents to obtain (3S,5S)-methanesulfonic acid5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yl ester (3.35g) as a slightly yellow syrup, MS: 476 (MH⁺).

[0600] In analogy:(3S,5R)-3-[4-Hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (1.10 g) gave(2S,4S)-3-[4-methanesulfonyloxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (0.32 g) as a colourless solid, MS: 534 (MH⁺).

[0601](3R,5S)-1-(Naphthalene-2-sulfonyl)-5-(3-phenyl-propoxymethyl)-pyrrolidin-3-ol(0.88 g) gave methanesulfonic acid(3S,5S)-1-(naphthalene-2-sulfonyl)-5-(3-phenyl-propoxymethyl)-pyrrolidin-3-ylester (0.68 g) as a foam. The compound was used in the next step withoutpurification.

[0602](3S,5R)-1-(Naphthalene-2-sulfonyl)-5-phenoxymethyl-pyrrolidin-3-ol (0.75g) gave (3S,5S)-methanesulfonic acid1-(naphthalene-2-sulfonyl)-5-phenoxymethyl-pyrrolidin-3-yl ester (0.65g) as a syrup, MS: 462 (MH⁺).

[0603] To a solution of (3S,5S)-methanesulfonic acid5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yl ester (3.0g) in abs DMF (60 ml) was added potassium thioacetate (1.08 g). Thereaction mixture was stirred for 1 h at 100° C. and concentrated underoil pump vacuum. The residue was treated with ice/water and extractedwith EtOAc. The organic phase was washed with water and brine, driedover magnesium sulphate and concentrated. The residue waschromatographed on silica gel using EtOAc/hexane 1:3 as eluent to obtain(3S,5R)-thioacetic acidS-[5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yl]ester(2.16 g) as a slightly yellow powder, MS: 334 (M−121).

[0604] In analogy:(2S,4S)-3-[4-Methanesulfonyloxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (0.30 g) was reacted as described above to obtain(2S,4R)-3-[4-acetylsulfanyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (0.23 g) as a thick syrup, MS: 514 (MH⁺).

[0605] Crude methanesulfonic acid(3S,5S)-1-(naphthalene-2-sulfonyl)-5-(3-phenyl-propoxymethyl)-pyrrolidin-3-yleste (0.64 g) gave thioacetic acid (3R,5S)—S-[1-(naphthalene-2-sulfonyl)-5-(3-phenyl-propoxymethyl)-pyrrolidin-3-yl]ester (0.26 g) as a syrup, MS: 484 (MH⁺)

[0606] (3S,5S)-Methanesulfonic acid1-(naphthalene-2-sulfonyl)-5-phenoxymethyl-pyrrolidin-3-yl ester (0.62gave (3R,5S)-thioacetic acidS-[1-(naphthalene-2-sulfonyl)-5-phenoxymethyl-pyrrolidin-3-yl] ester(0.52 g) as a slightly coloured powder, MS: 442 (MH⁺).

[0607] (3S,5R)-Thioacetic acidS-[5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yl] ester(1.91 g) was reacted as described above in S-Acetyl deprotection toobtain(3S,5R)-5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiol(1.15 g) as an off-white solid, mp 79-80° C., MS: 413 (M).

[0608] In analogy:(2S,4R)-3-[4-Acetylsulfanyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (0.53 g) was reacted as described above in S-Acetyldeprotection to obtain(2S,4R)-3-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethoxymethyl]-benzoicacid methyl ester (0.23 g) as a thick syrup, MS: 471 (M)

[0609] Thioacetic acid(3R,5S)—S-[i-(naphthalene-2-sulfonyl)-5-(3-phenyl-propoxymethyl)-pyrrolidin-3-yl]ester (0.20 g) was reacted as described above in S-Acetyl deprotectionto obtain(3R,5S)-1-(naphthalene-2-sulfonyl)-5-(3-phenyl-propoxymethyl)-pyrrolidine-3-thiol(0.17 g) as a syrup, MS: 442 (MH⁺).

[0610] (3R,5S)-Thioacetic acidS-[1-(naphthalene-2-sulfonyl)-5-phenoxymethyl-pyrrolidin-3-yl] ester(0.35 g) was reacted as described above in S-Acetyl deprotection toobtain(3R,5S)-1-(naphthalene-2-sulfonyl)-5-phenoxymethyl-pyrrolidine-3-thiol(0.21 g) as a thick syrup, MS: 399 (M).

[0611] 6-ring: To rac-cis-Piperidine-2,5-dicarboxylic acid dimethylester [Frank J., J. Heterocyclic Chem. 32, 857-861 (1995)] (36.2 g)dissolved in dichloromethane (720 ml) were added 4-dimethylaminopyridine(33.0 g) and, dropwise, methanesulphonyl chloride (28.6 g) within 10minutes and room temperature. The temperature rose to 35° C. Thereaction mixture was stirred 1 h at room temperature, washed with 2molar HCJ, sodium carbonate-solution and brine, dried over magnesiumsulphate and concentrated to dryness to obtain(2RS,5RS)-1-methanesulfonyl-piperidine-2,5-dicarboxylic acid dimethylester (46.8 g) as a syrup, MS: 220 (M+-59).

[0612] In analogy: rac-cis-Piperidine-2,5-dicarboxylic acid dimethylester with naphthalene-2-sulphonyl chloride gave(2RS,5RS)-1-(naphthalene-2-sulfonyl)-piperidine-2,5-dicarboxylic aciddimethyl ester (36.3 g) as a colourless solid, mp 94-96° C., MS: 392(MH⁺).

[0613] To a solution of a 16:9 mixture of meso- and(3RS,5RS)-piperidine-3,5-dicarboxylic acid dimethyl ester [Stetter, H. &Henning, H., Chem. Ber. 88, 789-795 (1955)] (23.0 g) in dichloromethane(460 ml) and triethylamine (30 ml) was added naphthalene-2-sulphonylchloride (24.5 g) in dichloromethane (50 ml) in 15 minutes at roomtemperature. The reaction mixture was boiled under reflux for 4 h,cooled down and washed with water and sodium bicarbonate solution, driedover magnesium sulphate and concentrated. The residue waschromatographed on silica gel using EtOAc/hexane 1:3, 1:2 and 1:1 aseluents to obtain a racemic mixture ofmeso-1-(naphthalene-2-sulfonyl)-piperidine-3,5-dicarboxylic aciddimethyl ester (22.6 g) as a colourless solid, mp 123-125° C., MS: 360(M⁺−31).

[0614] To a solution of(2RS,5RS)-1-methanesulfonyl-piperidine-2,5-dicarboxylic acid dimethylester (46.5 g) in methanol (850 ml) and water (85 ml) was added 1 molarsodium hydroxide (166 ml) within 20 minutes at reflux temperature. Thereaction mixture was stirred for 45 minutes at reflux, cooled andconcentrated. The residue was taken up in water (300 ml) and washed withEt₂O. The aqueous phase was acidified with 1 molar HCl (166 ml) andextracted with EtOAc. The organic phase was washed with brine, driedover magnesium sulphate and concentrated. The residue was crystallizedfrom acetone/Et₂O to obtain(2RS,5RS)-1-methanesulfonyl-piperidine-2,5-dicarboxylic acid 2-methylester (16.8 g) as a colourless solid, mp 130-133° C., MS: 206 (M⁺−59).

[0615] In analogy:(2RS,5RS)-1-(Naphthalene-2-sulfonyl)-piperidine-2,5-dicarboxylic aciddimethyl ester (16.0 g) gave(2RS,5RS)-1-(naphthalene-2-sulfonyl)-piperidine-2,5-dicarboxylic acid2-methyl ester (6.25 g) as a colourless solid, MS: 377 (M⁺).

[0616] Meso-1-(naphthalene-2-sulfonyl)-piperidine-3,5-dicarboxylic aciddimethyl ester (3.0 g) gave(3RS,5SR)-1-(naphthalene-2-sulfonyl)-piperidine-3,5-dicarboxylic acidmonomethyl ester (1.58 g) as a colourless amorphous powder, MS: 378(MH⁺).

[0617] To a solution of(2RS,5RS)-1-methanesulfonyl-piperidine-2,5-dicarboxylic acid 2-methylester (10.7 g) in tetrahydrofuran was added a 1 M borane solution intetrahydrofuran (215 ml) within 0.5 h at 0° C. The reaction mixture wasstirred for 4 h at 0° C., poured onto ice/saturated sodium bicarbonatesolution and concentrated. The aqueous residue was extracted with EtOAc.The organic phase was washed with brine, dried over magnesium sulphateand concentrated. The residue was chromatographed on silica gel usingEtOAc/hexane 1:1 and 3:2 as eluents to obtain(2RS,5RS)-5-hydroxymethyl-1-methanesulfonyl-piperidine-2-carboxylic acidmethyl ester (8.1 g) as a colourless solid, MS: 206 (100%, M⁺−59).

[0618] In analogy:(2RS,5RS)-1-(Naphthalene-2-sulfonyl)-piperidine-2,5-dicarboxylic acid2-methyl ester (1.80 g) gave(2RS,5RS)-5-hydroxymethyl-1-(naphthalene-2-sulfonyl)-piperidine-2-carboxylicacid methyl ester (1.45 g) as a colourless foam, MS: 364 (MH⁺).

[0619] (3RS,5SR)— 1-(Naphthalene-2-sulfonyl)-piperidine-3,5-dicarboxylicacid monomethyl ester (1.50 g) gave(3SR,5RS)-5-hydroxymethyl-1-(naphthalene-2-sulfonyl)-piperidine-3-carboxylicacid methyl ester (0.86 g) as a syrup, MS: 364 (MH⁺).

[0620](3SR,5RS)-5-Hydroxymethyl-1-(naphthalene-2-sulfonyl)-piperidine-3-carboxylicacid methyl ester (4.8 g) was reacted as described in Example 16(R²-ether formation) to obtain(3SR,5RS)-5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidine-3-carboxylicacid methyl ester (5.4 g) as a colourless gum, MS: 454 (MH⁺).

[0621] In analogy:(2RS,5RS)-5-Hydroxymethyl-1-(naphthalene-2-sulfonyl)-piperidine-2-carboxylicacid methyl ester (1.82 g) gave(2RS,5RS)-5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidine-2-carboxylicacid methyl ester (1.60 g) as a light yellow gum, MS: 454 (MH⁺).

[0622](2RS,5RS)-5-Hydroxymethyl-1-methanesulfonyl-piperidine-2-carboxylic acidmethyl ester (3.01 g) gave(2RS,5RS)-5-benzyloxymethyl-1-methanesulfonyl-piperidine-2-carboxylicacid methyl ester (2.80 g) as a colourless gum, MS: 282 (M-59).

[0623](3SR,5RS)-5-Benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidine-3-carboxylicacid methyl ester (2.70 g) was reduced with lithium aluminium hydride asdescribed in Example 17 to obtain(3SR,5RS)-[5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidin-3-yl]-methanol(1.54 g) as a syrup, MS: 426 (MH⁺).

[0624] In analogy:(2RS,5RS)-5-Benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidine-2-carboxylicacid methyl ester (1.30 g) gave(2RS,5RS)-[5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidin-2-yl]-methanol(0.67 g) as a light yellow viscous oil, MS: 426 (MH⁺).

[0625](2RS,5RS)-5-Benzyloxymethyl-1-methanesulfonyl-piperidine-2-carboxylicacid methyl ester (2.70 g) gave(2RS,5RS)-(5-benzyloxymethyl-1-methanesulfonyl-piperidin-2-yl)-methanol(1.70 g) as a light yellow syrup, MS: 282 (M-31).

[0626](3SR,5RS)-[5-Benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidin-3-yl]-methanol(1.35 g) was reacted with thioacetic acid (see Mitsunobu reactiondescribed in Example 17) to obtain thioacetic acid(3SR,5RS)—S-[5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidin-3-ylmethyl]ester (0.92 g) as a syrup, MS: 484 (MH⁺).

[0627] In analogy:(2RS,5RS)-[5-Benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidin-2-yl]-methanol(0.64 g) gave thioacetic acid(2RS,5RS)—S-[5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidin-2-ylmethyl]ester (0.48 g) as a light yellow syrup, MS: 484 (MH⁺).

[0628](2RS,5RS)-(5-Benzyloxymethyl-1-methanesulfonyl-piperidin-2-yl)-methanol(1.41 g) gave thioacetic acid(2RS,5RS)—S-(5-benzyloxymethyl-1-methanesulfonyl-piperidin-2-ylmethyl)ester (0.95 g) as a light brown gum, MS: 372 (MH⁺).

[0629] Thioacetic acid(3SR,5RS)—S-[5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidin-3-ylmethyl]ester (0.88 g) gave(3SR,5RS)-[5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidin-3-yl]-methanethiol(0.92 g) as a syrup, MS: 442 (MH⁺).

[0630] In analogy: Thioacetic acid(2RS,5RS)—S-[5-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidin-2-ylmethyl]ester (0.34 g) gave(2RS,5RS)-5-Benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidin-2-yl]-methanethiol(0.23 g) as a colourless syrup, MS: 442 (MH⁺).

[0631] Thioacetic acid(2RS,5RS)—S-(5-benzyloxymethyl-1-methanesulfonyl-piperidin-2-ylmethyl)ester (0.78 g) gave(2RS,5RS)-(5-benzyloxymethyl-1-methanesulfonyl-piperidin-2-yl)-methanethiol(0.54 g) as a colourless syrup, MS: 330 (MH⁺).

Example 18 Ethers, 3,4-Substituted Pyrrolidine-Ethers

[0632] To a solution of (3RS,4RS)-pyrrolidine-3,4-dicarboxylic aciddiethyl ester (2.04 g, 9.48 mmol) [Bull. Soc. Chim. Fr. 1988, 579] indichloromethane (30 ml) was added pyridine (1.12 g, 14.22 mmol),N,N-dimethylaminopyridine (10 mg) and methanesulfonyl chloride (1.30 g,11.38 mmol) and stirred for 2 h at RT The solution was washed with 0.5 Maqueous HCl and water, dried and evaporated. Flash chromatography(EtOAc/hexane 1:1) gave 1.6 g (42%) of(3RS,4RS)-1-methanesulfonyl-pyrrolidine-3,4-dicarboxylic acid diethylester as a colorless solid, MS: 310 (M+NH₄)+.

[0633] In analogy:(3RS,4RS)-1-(Naphthalene-2-sulfonyl)-pyrrolidine-3,4-dicarboxylic aciddiethyl ester was obtained (44%) as a colorless solid, MS: 410 (MH⁺).

[0634] To a solution of(3RS,4RS)-1-methanesulfonyl-pyrrolidine-3,4-dicarboxylic acid diethylester (1.13 g, 3.85 mmol) in THF (40 ml) was slowly added a 1 M solutionof LiAlH₄ in THF (11.55 ml. 11.55 mmol) at 0° C. The mixture was stirredfor 1.5 h at 0° C. Water (0.44 ml), 1 M aqueous NaOH (0.44 ml) and water(1.31 ml) were added subsequently at 0° C. MgSO₄ was added and filtered.The solid was washed with EtOAc (4×). The filtrate was evaporated toleave a colorless solid that was washed with hot dichloromethane to give([3RS,4RS]-4-hydroxymethyl-1-methanesulfonyl-pyrrolidin-3-yl)-methanolas a colorless solid, MS: 268 (M+OAc)⁻.

[0635] In analogy:(3RS,4RS)-[4-Hydroxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yl]-methanolwas obtained (74%) from(3RS,4RS)-1-(naphthalene-2-sulfonyl)-pyrrolidine-3,4-dicarboxylic aciddiethyl ester as a colorless solid, MS: 321 (M)⁺.

[0636] To a suspension of 60% NaH (66 mg, 1.64 mmol) in DMF (3 ml) wasadded a solution of([3RS,4RS]-4-hydroxymethyl-1-methanesulfonyl-pyrrolidin-3-yl)-methanol(327 mg, 1.56 mmol) in DMF (5 ml) at −12° C. After 5 min, benzylbromide(286 mg, 1.64 mmol) was added and the mixture was stirred at −12° C. for30 min. The mixture was allowed to warm to room temperature. The solventwas evaporated. Water was added and extracted with dichloromethane. Theorganic phase was dried, filtered and evaporated. Flash chromatography(hexane/EtOAc 2:1=>1:1) gave 275 mg (58%) of([3RS,4RS]-4-benzyloxymethyl-1-methanesulfonyl-pyrrolidin-3-yl)-methanolas a colorless oil, MS: 358 (M+OAc)⁻.

[0637] To a solution of([3RS,4RS]-4-benzyloxymethyl-1-methanesulfonyl-pyrrolidin-3-yl)-methanol(267 mg, 0.89 mmol) and triethylamine (372 ml, 2.67 mmol) in Et₂O (4 ml)was slowly added methanesulfonyl chloride (137 ml, 1.78 mmol) at −20° C.After 15 min the mixture was allowed to warm to room temperature 1 Maqueous HCl (0.5 ml) was added. The organic phase was washed with water,dried, filtered and evaporated to give a colorless oil (264 mg). DMF(2.5 ml) and potassium thioacetate (120 mg, 1.05 mmol) were added andthe mixture was heated to 100° C. for 1 h. Dichloromethane was added andwashed with water. The organic phase was dried, filtered and evaporated.Flash chromatography (EtOAc/hexane 1:1) gave 151 mg (48%) of thioaceticacid(3RS,4RS)—S-(4-benzyloxymethyl-1-methanesulfonyl-pyrrolidin-3-ylmethyl)ester as a light yellow solid, MS: 416 (M+OAc)⁻.

[0638] To a solution of LiAlH₄ (0.23 mmol, 1 M in THF) in Et₂O (6 ml)was added a suspension of thioacetic acid(3RS,4RS)—S-(4-benzyloxymethyl-1-methanesulfonyl-pyrrolidin-3-ylmethyl)ester (75.5 mg, 0.21 mmol) in Et₂O. The mixture was stirred at RT for 30min and refluxed for 2 h. After cooling to r.t., water and 1 M aqueousHCl were added. The organic phase was dried and evaporated to give 63 mg(95%) of[(3RS,4RS)-4-benzyloxymethyl-1-methanesulfonyl-pyrrolidin-3-yl]-methanethiolas a colorless oil, MS: 333 (M+NH₄)⁺.

[0639] A solution of([3RS,4RS]-4-hydroxymethyl-1-methanesulfonyl-pyrrolidin-3-yl)-methanol(316 mg, 1.51 mmol), tosylchloride (288 mg, 1.51 mmol),N,N-dimethylaminopyridine (10 mg) and triethylamine (153 mg, 1.51 mmol)in THF (10 ml) was stirred overnight at room temperature Dichloromethaneand 1 M aqueous HCl were added. The organic phase was separated. Theaqueous phase was extracted with dichloromethane. The combined organicphases were washed with water, dried and evaporated to give the crudetosylate as a colorless oil.

[0640] To a solution of triphenylmethane thiol (639 mg, 2.26 mmol) inDMF (3 ml) was added KotBu (220 mg, 1.96 mmol) at 0° C. and stirred for20 min. A solution of the crude tosylate in DMF was added and stirredfor 3 h at room temperature. Water was added and the mixture wasextracted with dichloromethane. The organic phase was dried, filteredand evaporated. Flash chromatography(dichloromethane=>dichloromethane/MeOH 95:5) gave 236 mg (33%) of[(3RS,4RS)-1-methanesulfonyl-4-tritylsulfanylmethyl-pyrrolidin-3-yl]-methanolas a colorless foam, MS: 526 (M+OAc)⁻.

[0641] In analogy:(3RS,4RS)-1-l(Naphthalene-2-sulfonyl)-4-tritylsulfanylmethyl-pyrrolidin-3-yl]-methanolwas obtained (55%) from(3RS,4RS)-[4-hydroxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yl]-methanolas a colorless foam, MS: 602 (M+Na)⁺.

[0642] To a solution of[(3RS,4RS)-1-methanesulfonyl-4-tritylsulfanylmethyl-pyrrolidin-3-yl]-methanol(106 mg, 0.226 mmol) in THF (15 ml) were added triethylamine (47 ml,0.34 mmol) and methanesulfonyl chloride (26 ml, 0.34 mmol) at 0° C. Themixture was stirred at 0° C. for 30 min and at RTfor 1 h. Water and 1 Maqueous HCl were added and the mixture was extracted with EtOAc. Theorganic phase was dried, filtered and evaporated to give the crudemesylate as a colorless oil.

[0643] To a suspension of 60% NaH (14 mg, 0.339 mmol) in DMF (1 ml) wasadded phenol (43 mg, 0.452 mmol) and stirred for 15 min. A solution ofthe crude mesylate in DMF was added and the mixture was stirred for 8 h.Water was added and the mixture was extracted with dichloromethane. Theorganic phase was dried, filtered and evaporated. Flash chromatography(hexane/EtOAc 4:1=>1:1) gave 52 mg (43%) of(3RS,4RS)-1-methanesulfonyl-3-phenoxymethyl-4-tritylsulfanylmethyl-pyrrolidineas a colorless foam, MS: 566 (M+Na)⁺.

[0644] In analogy:(3RS,4RS)-1-(Naphthalene-2-sulfonyl)-3-phenoxymethyl-4-tritylsulfanylmethyl-pyrrolidinewas obtained (43%) from(3RS,4RS)-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanylmethyl-pyrrolidin-3-yl]-methanolas a colorless oil, MS: 656 (MH⁺).

[0645] To a solution of(3RS,4RS)-[1-(naphthalene-2-sulfonyl)-4-tritylsulfanylmethyl-pyrrolidin-3-yl]-methanol(200 mg, 0.345 mmol) in DMF (2 ml) was added 60% NaH (15.2 mg, 0.379mmol) at 0° C. and stirred for 10 min. Benzyl bromide (45 μl, 0.379mmol) was added and stirred for 30 min at 0° C. and for 1 h at roomtemperature. Water was added and the mixture was extracted withdichloromethane. The organic phase was dried, filtered and evaporated.Flash chromatography (hexane/EtOAc 4:1=>1:1) gave 140 mg (61%) of(3RS,4RS)-1-(naphthalene-2-sulfonyl)-3-benzyloxymethyl-4-tritylsulfanylmethyl-pyrrolidineas a colorless foam, MS: 692 (M+Na)⁺.

[0646] To a solution of(3RS,4RS)-1-methanesulfonyl-3-phenoxymethyl-4-tritylsulfanyl-methyl-pyrrolidine(50 mg, 0.092 mmol) in trifluoroacetic acid (1.4 ml, 18.4 mmol) wasadded triethylsilane (107 mg, 0.92 mmol) at 0° C. The mixture wasstirred for 30 min at 0° C. The solvent was evaporated at roomtemperature. Flash chromatography (dichloromethane=>dichloromethane/MeOH98:2) gave 27 mg (97%) of[(3RS,4RS)-1-methanesulfonyl-4-phenoxymethyl-pyrrolidin-3-yl]-methanethiolas a colorless oil, MS: 301 (M)⁺.

[0647] In analogy:(3RS,4RS)-[1-(Naphthalene-2-sulfonyl)-4-phenoxymethyl-pyrrolidin-3-yl]-methanethiolwas obtained (88%) from (3RS,4RS)—1-(naphthalene-2-sulfonyl)-3-phenoxymethyl-4-tritylsulfanylmethyl-pyrrolidineas a colorless oil, MS: 414 (MH⁺).

[0648](3RS,4RS)-[4-Benzyloxymethyl-1-(naphthalene-2-sulfonyl)-pyrrolidin-3-yl]-methanethiolwas obtained (quant.) from(3RS,4RS)-1-(naphthalene-2-sulfonyl)-3-benzyloxymethyl-4-tritylsulfanylmethyl-pyrrolidineas a colorless oil, MS: 428 (MH⁺).

Example 19 6-Ring Ether

[0649] A suspension of 31.15 g (150 mmol) 3-Ethoxycarbonyl-4-piperidonehydrochloride was suspended in 400 ml hexamethyldisilazane and heatedunder reflux (140° C.) for 2.5 h. The solution was evaporated complete,the residue dissolved in 400 ml THF and treated with 34 g (150 mmol) ofnaphthalene-2-sulfonylchloride in 150 ml THF. The reaction was stirred16 h at room temperature, evaporated, treated with 400 ml aqueous 10%NaCl, stirred for 10 min and extracted with EtOAc (3×400 ml). Theorganic phase was dried (Na₂SO₄) and evaporated and crystallized fromEt₂O at 5° C. to give 53.1 g (90%) of4-hydroxy-1-(naphthalene-2-sulfonyl)-1,2,5,6-tetrahydro-pyridine-3-carboxylicacid ethyl ester, MS: 362 (MH⁺).

[0650] In analogy: 3-Ethoxycarbonyl-4-piperidone hydrochloride andmethanesulfonyl chloride gave4-hydroxy-1-methanesulfonyl-1,2,5,6-tetrahydro-pyridine-3-carboxylicacid ethyl ester, mp 87-88° C., MS: 250 (MH⁺).

[0651] A suspension of 28.9 g (80 mmol)4-hydroxy-1-(naphthalene-2-sulfonyl)-1,2,5,6-tetrahydro-pyridine-3-carboxylicacid ethyl ester in 150 ml MeOH was cooled to room temperature andtreated in portion with 3.03 g (80 mmol) of NaBH4. After 3 h thereaction was adjusted to pH 4 with AcOH, evaporated and treated withaqueous saturated NaHCO₃/EtOAc (3×). The organic phase was dried(Na₂SO₄) and evaporated to give 29.3 g (quant.) of 1:1 mixture of(3RS,4RS)- and(3RS,4SR)-4-hydroxy-1-(naphthalene-2-sulfonyl)-piperidine-3-carboxylicacid ethyl ester, MS: 364 (MH⁺).

[0652] In analogy:4-Hydroxy-1-methanesulfonyl-1,2,5,6-tetrahydro-pyridine-3-carboxylicacid ethyl ester gave a 1:1 mixture of (3RS,4RS)- and(3RS,4SR)-4-hydroxy-1-methanesulfonyl-piperidine-3-carboxylic acid ethylester which was immediately used for the next reaction.

[0653] A solution of 23.8 g (65 mmol) 1:1 mixture of (3RS,4RS)- and(3RS,4SR)-4-hydroxy-1-(naphthalene-2-sulfonyl)-piperidine-3-carboxylicacid ethyl ester in 400 ml CH₂Cl₂ was treated at 0° C. with 5.56 ml(71.5 mmol) methanesulfonyl chloride, 7.85 ml (97.5 mmol) pyridine and7.94 g (65 mmol) DMAP. The reaction was stirred 24 h at room temperatureand partitioned between aqueous 1 N HCl/Et₂O (3×). The organic phaseswere washed with aqueous 10% NaCl solution, dried over Na₂SO₄ andevaporated to give 28.75 g (quantitative) of a 1:1 mixture of (3RS,4RS)-and (3RS,4SR)4-methanesulfonyloxy-1-(naphthalene-2-sulfonyl)-piperidine-3-carboxylicacid ethyl ester.

[0654] 2.76 ml (17.83 mmol) of 4-methoxybenzyl mercaptan was slowlyadded at room temperature to a solution of 1.83 g (16.35 mmol) ofpotassium tert-butylate in 60 ml DMF and stirred mechanically for 20min. Then 6.56 g (14.86 mmol) of a 1:1 mixture of (3RS,4RS)- and(3RS,4SR)4-methanesulfonyloxy-1-(naphthalene-2-sulfonyl)-piperidine-3-carboxylicacid ethyl ester in 60 ml DMF were slowly added at 20° C. The reactionwas stirred for 45 min at room temperature, and partitioned betweencooled saturated aqueous NH₄Cl/EtOAc (3×300). The organic phases werewashed with aqueous 10% NaCl, dried (Na₂SO₄) and evaporated. Flashchromatography on silica gel (toluene/CH₃CN 97.5:2.5 to 95:5) gave 4.00g (54%) of 1:1 mixture of (3RS,4RS)- and(3RS,4SR)-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-piperidine-3-carboxylicacid ethyl ester, MS: 500 (MH⁺).

[0655] In analogy: A 1:1 mixture of (3RS,4RS)- and(3RS,4SR)-4-hydroxy-1-methanesulfonyl-piperidine-3-carboxylic acid ethylester gave via a 1:1 mixture of (3RS,4RS)- and(3RS,4SR)-1-methanesulfonyl-4-methanesulfonyloxy-piperidine-3-carboxylicacid ethyl ester a 1:1 mixture of (3RS,4RS)- and(3RS,4SR)-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-piperidine-3-carboxylicacid ethyl ester, MS: 388 (MH⁺).

[0656] 1.2 ml (1.2 mmol, IM THF solution) of LAH was added during 5 minto a cold solution (−20° C.) of 500 mg (1.2 mmol) in 10 ml THF. Thereaction was stirred for 20 min, cooled to −78° C. and quenched with asuspension of 0.3 g silica gel/0.3 g MgSO₄₀.7H₂O in 2 ml aqueous 10%KHSO₄. After the addition of 0.5 ml H₂O, the suspension was stirred for10 min at room temperature, filtered and washed with THF. Afterevaporation of the THF, the residue was taken up in CH₂Cl₂, dried overNa₂SO₄, evaporated and oile out of Et₂O/pentane to give 430 mg (94%) of1:1 mixture of (3RS,4RS)- and(3RS,4SR)-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-piperidin-3-yl]-methanol,MS: 458 (MH⁺).

[0657] In analogy: 1:1 Mixture of (3RS,4RS)- and(3RS,4SR)-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-piperidine-3-carboxylicacid ethyl ester gave a 1:1 mixture of (3RS,4RS)- and(3RS,4SR)-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-piperidin-3-yl]-methanol,MS: 345 (M).

[0658] 150 mg (0.3 mmol) of (3RS,4RS)- and(3RS,4SR)-[4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-piperidin-3-yl]-methanoland 0.039 ml (0.33 mmol) of benzylbromide were dissolved in 15 ml DMF,cooled to 0° C. and treated with 14.4 mg (0.33 mmol) of 55% NaH and acatalytic amount of NaI. The reaction was warmed up over night andtreated with saturated NH₄Cl solution/EtOAc (3×). The organic phase waswashed with 10% NaCl solution, dried over Na₂SO₄ and evaporated.Flash-chromatography on silica gel (toluene/CH₃CN 98:2) gave 90 mg (20%)of(3SR,4RS)-3-benzyloxymethyl-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-piperidine(proven by ¹H-NMR, NOE), MS: 548 (MH⁺) and 77 mg (17%) of(3SR,4SR)-3-benzyloxymethyl-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-piperidine(profane by ¹H-NMR, NOE), MS: 548 (MH⁺) and 110 mg (24%) of a 1:1mixture of both diastereomers.

[0659] In analogy: 1:1 Mixture of (3RS,4RS)- and(3RS,4SR)-[1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-piperidin-3-yl]-methanolgave(3RS,4RS)-3-Benzyloxymethyl-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-piperidine,MS: 435 (M)

[0660] and(3RS,4SR)-3-benzyloxymethyl-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-piperidine,MS: 435 (M).

[0661] Method 1: 84 mg (0.153 mmol)(3SR,4RS)-3-Benzyloxymethyl-4-(4-methoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-piperidinewere dissolved in 2 ml TFA and treated at 0° C. with 0.244 ml (1.53mmol) of triethylsilane. After 2 h at 0° C. and 18 h at roomtemperature, the mixture was evaporated and purified by precipitationwith Et₂O/pentane to give 40 mg (61%) of(3SR,4RS)-3-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidine-4-thiol,MS: 427 (M).

[0662] In analogy:(3SR,4SR)-3-Benzyloxymethyl-4-(4-rmethoxy-benzylsulfanyl)-1-(naphthalene-2-sulfonyl)-piperidinegave(3SR,4SR)-3-benzyloxymethyl-1-(naphthalene-2-sulfonyl)-piperidine-4-thiol,MS: 428 (MH⁺).

[0663](3RS,4RS)-3-Benzyloxymethyl-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-piperidinegave (3RS,4RS)-3-benzyloxymethyl-1-methanesulfonyl-piperidine-4-thiol,MS: 316 (MH⁺).

[0664](3RS,4SR)-3-Benzyloxymethyl-1-methanesulfonyl-4-(4-methoxy-benzylsulfanyl)-piperidinegave (3RS,4SR)-3-benzyloxymethyl-1-methanesulfonyl-piperidine-4-thiol,MS: 316 (MH⁺).

Example 20 Synthesis of Tert. Thiols

[0665] Oxo-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester wrereprepared from BOC-Hyp-OH following literature procedure [Baldwin, JackE.; Field, Robert A.; Lawrence, Christopher C.; Merritt, Kristen D.;Schofield, Christopher J.; Tetrahedron Lett.; 34; 1993; 7489-7492; andHerdewijn, Piet; Claes, Paul J.; Vanderhaeghe, Hubert; Can.J.Chem.; 60;1982; 2903-2907;]

[0666] To a solution of methylenetriphenyl phosphorane, previouslyprepared from 37 g (777 mmol, 50% NaH in mineral oil, 4 eq) and 277.6 g(777 mmol, 4 eq) methyltriphenyl-phosphonium bromide in 1.5 l THF bystirring at 50° C. for 4 h, were added 44.5 g (194 mmol, leq)(2S)-4-Oxo-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester in 300ml over a period of 30 min at RT. The suspension was stirred at 50° C.over night. After cooling to RT the suspension was added to a 5% NaHCO₃solution, washed with ether, the inorganic phase was acidified andextracted with EtOAc, washed with brine, dried over Na₂SO₄ andevaporated. 32.1 g (72%) (2S)-4-Methylene-pyrrolidine-1,2-dicarboxylicacid 1-tert-butyl ester were isolated as white solid.

[0667] To 14.7 g (64.7 mmol)(2S)-4-Methylene-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester in80 ml THF were added 7.13 ml (64.7 mmol, 1.0 eq) N-methylmorpholine and8.5 ml (64.0 mmol, 1.0 eq) isobutylchloro formate at −5° C. and thesolution was stirred at that temperature for 1.5 h. The mixture wasfiltered and added to a suspension of 3.7 g (97.8 mmol, 1.5 eq) NaBH₄ in30 ml water over a period of 25 min at 0° C. The reaction was stirred at0° C. for 2 h and at RT over night. Ether was added, the layers wereseparated and the inorganic layer was extracted with ether and CH₂Cl₂,the organic layers were washed with brine, dried over Na₂SO₄, filteredand evaporated, yielding 9.3 g (68%)(2S)-2-Hydroxymethyl-4-methylene-pyrrolidine-1-carboxylic acidtert-butyl ester as light brown oil, MS: 182 (M-CH₂OH.).

[0668] To 9.6 g (45 mmol)(2S)-2-Hydroxymethyl-4-methylene-pyrrolidine-1-carboxylic acidtert-butyl ester and 25 g (112.5 mmol, 2.5 eq) 2,4,5-trifluorobenzylbromide in 950 ml THF were added 3.2 g (73.1 mmol, 50% in mineral oil,1.6 eq) NaH at 0° C. over a period of 30 min. The reaction was warmed toRT over night, and added to a cooled mixture of saturated aqueous NH₄Clsolution and EtOAc, the phases were separated and the inorganic one wasextracted with EtOAc, the combined organic ones were washed with brine,dried over Na₂SO₄, filtered and evaporated. The crude product waspurified by flash chromatography using hexane/EtOAc 4:1 as an eluentyielding 5.4 g (34%)(2S)-4-Methylene-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester as yellow oil, MS: 358 (MH⁺) and 1.7 g (13%)recovered starting material.

[0669] To 3.7 g (10.4 mmol)(2S)-4-Methylene-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester in 160 ml CH₂Cl₂ were added 5.1 g (20.8 mmol, 2eq) 3-chloroperoxybenzoic acid. The mixture was stirred at RT overnight, Na₂S₂O₃ solution was added and the reaction was stirred for 1.5h. The phases were separated and the inorganic one was extracted withether. The organic phases were washed with 1M NaOH and brine, dried overNa₂SO₄, filtered and evaporated yielding 3.9 g crude product as amixture of (3R,6S)- and(3S,6S)-6-(2,4,5-trifluoro-benzyloxymethyl)-1-oxa-5-aza-spiro[2.4]heptane-5-carboxylicacid tert-butyl, MS: 374 (MH⁺).

[0670] g (10.4 mmol) crude mixture of (3R,6S)- and(3S,6S)-6-(2,4,5-trifluoro-benzyloxymethyl)-1-oxa-5-aza-spiro[2.4]heptane-5-carboxylic acid tert-butyl were dissolved in 20 ml EtOHand were treated with 2.07 g (20.8 mmol, 2 eq) potassium rhodamide in 2ml H₂O for 16 h at RT. The mixture was concentrated, redissolved inEtOAc and washed with brine, dried over Na₂SO₄, filtered and evaporated.The crude material was purified by flash chromatography yielding 1.84 g(45%,2 steps) a mixture of (3R,6S)- and(3S,6S)-6-(2,4,5-trifluoro-benzyloxymethyl)-1-thia-5-aza-spiro[2.4]heptane-5-carboxylicacid tert-butyl ester in the ratio 5:1, MS: 390 (MH⁺).

[0671] To 70 mg (0.18 mmol) (major diastereomer) in 3 ml THF were added1.08 ml (1.08 mmol, 10 eq) 1M lithium triethylborohydride in THF. After1 h the reaction was stopped by the addition of saturated aqueous NH₄Clsolution and the temperature was raised to RT. The mixture was extractedwith EtOAc, the organic phases were washed with brine, dried overNa₂SO₄, filtered and concentrated.

[0672] The material was dissolved in 5.7 ml trifluoro ethanol and 3.8 mlCH₂Cl₂ and treated with 44,3 ji (0.17 mmol) tri-n-butyl phosphine and 19tll H₂O at 0° C. The solution was stirred for 45 min, concentrated andpurified by flash chromatography with hexane/EtOAc 4:1 yielding 23 mg(33%, 2 steps)(2S,4R)-4-Mercapto-4-methyl-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester as yellow oil, MS: 392 (MH⁺).

[0673] Analogously, the following compound was prepared from the minordiastereomer:(2S,4S)-4-Mercapto-4-methyl-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid tert-butyl ester colorless oil, MS: 392 (MH⁺).

Example 21.a S-Acetyl and Benzoyl-Compounds

[0674] A solution of 10 g (21.96 mmol)(2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo [1,4]dioxin-5-yl ester in 130 ml pyridine weretreated at 0° C. with 3.12 ml (43.92 mmol) acetyl chloride and stirredfor 6 h at RT. The reaction was poured on ice water and extracted witEt₂O (3×). The organic phases were washed with aqueous 1 N HCl and 10%NaCl, dried (Na₂SO4) and evaporated. Flash chromatography on silica gel(CH₂Cl₂/Et₂O 99.5:0.5 to 98:2) gave 9.94 g (91%)(2S,4R)-4-Acetylsulfanyl-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo[1,4]dioxin-5-yl ester, MS: 498 (MH⁺).

[0675] In analogy:(3R,5S)-5-Benzyloxymethyl-1-methanesulfonyl-pyrrolidine-3-thiol gaveThioacetic acid(3R,5S)—S-(5-benzyloxymethyl-1-methanesulfonyl-pyrrolidin-3-yl) ester,mp: 79-80° C.; MS: 344 (MH⁺);

[0676](3R,5S)-1-Methanesulfonyl-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-3-thiolgave Thioacetic acid(3R,5S)—S-[1-methanesulfonyl-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidin-3-yl]ester, MS: 398 (MH⁺);

[0677](2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2-methoxycarbonyl-phenyl ester gave(2S,4R)-4-Acetylsulfanyl-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2-methoxycarbonyl-phenyl ester, MS: 498 (MH⁺);

[0678]4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid butylamide gave (3R,5S)-Thioacetic acidS-[1-butylsulfamoyl-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidin-3-yl]ester, MS: 455 (MH⁺);

[0679](2S,4R)-1-[4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidin-1-yl]-3-methyl-butan-1-onegave (5S,3R)-Thioacetic acidS-[1-(3-methyl-butyryl)-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidin-3-yl]ester, MS: 404 (MH⁺);

[0680](2S,4R)-4-Mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo[1,4]dioxin-5-yl ester and benzoyl chloride gave(2S,4R)-4-Benzoylsulfanyl-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo[1,4]dioxin-5-yl, MS: 560 (MHL).

Example 21.b S-Acetyl and Benzoyl-Compounds

[0681] 534.1 mg (0.889 mmol)(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester in 15 ml CH₂Cl₂ were treated with 180 μl (1.08mmol, 1.27 eq) iPr₂NEt and 80 III (1.08 mmol, 1.2 eq) acetylchloride at0° C. 70 mg (0.11 mmol, 0.12 eq) 4-(N-benzyl-N-methylamino) pyridine,polymer-supported, were added, and the mixture was shaken for 1 h,before 220 mg (2.0 mmol/g, 0.44 mmol)polystyrene-divinylbenzene-supported tris(2-aminoethyl)amine[synthesized according to: Polymer-Supported Quenching Reagents forParallel Purification. Booth, R. John; Hodges, John C, J. Am. Chem. Soc.(1997), 119(21), 4882-4886.] were added.

[0682] After 1 h 700 μl (8.9 mmol, 10 eq) TFA were added carefully tothe mixture, followed by additional 700 μl (8.9 mmol, 10 eq) TFA after 1h, the reaction mixture was shaken for 3 h, and treated carefully with3.3 ml (20 mmol) iPr₂NEt, followed by 70 mg (0.11 mmol, 0.12 eq)4-(N-benzyl-N-methylamino)pyridine, polymer-supported, and 150 μl (1.16mmol, 1.3 eq) n-butyl chloro formate. After 45 min the mixture wasfiltered and the resin was washed thoroughly. To the organic phase wasadded saturated NaHCO₃ solution, the layers were separated, and theinorganic one was extracted with CH₂Cl₂, the organic phases were washedwith brine, dried over Na₂SO₄ and evaporated. Purification by flashchromatography EtOAc/hexane 1:3 yielded 330 mg (57%, 3 steps)[2S,4R]-2-{[acetyl-(2,5-difluoro-benzyl)-amino]-methyl}-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid butyl ester as light yellow oil which was dissolved in 10 ml CH₂Cl₂and treated with 400 μl (5.2 mmol, 10 eq) TFA and 1.1 ml (5.2 mmol, 10eq) triisopropyl silane for 30 min at 0° C. and 1 h at RT. The solutionwas added to a saturated solution of NaHCO₃, and the inorganic phase wasextracted with CH₂Cl₂, the organic phase was washed with brine, anddried over Na₂SO₄. Column chromatography with EtOAc/hexane 1:1 yielded156.5 mg (75%)[2S,4R]-2-{[acetyl-(2,5-difluoro-benzyl)-amino]-methyl}-4-mercapto-pyrrolidine-1-carboxylicacid butyl ester as light yellow oil, MS: 401 (MH⁺).

[0683] Analogously, the following compound was prepared from(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester and benzyl chloro formate:

[0684](2S,4R)-2-[[benzyloxycarbonyl-(2,5-difluoro-benzyl)-amino]-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid butyl ester as colorless oil, MS: 493 (MH⁺), via(2S,4R)-2-[[benzyloxycarbonyl-(2,5-difluoro-benzyl)-amino]-methyl]-4-tritylsulfanyl-pyrrolidine-1-carboxylicacid tert-butyl ester as colorless oil MS: 735 (MH⁺).

[0685] 130 mg (0.325 mmol)[2S,4R]-2-{[acetyl-(2,5-difluoro-benzyl)-amino]-methyl}-4-mercapto-pyrrolidine-1-carboxylicacid butyl ester in 3 ml pyridine were treated with 120,u 1(1.68 mmol,5.1 eq) acetyl chloride at 0° C. The resulting suspension was dilutedwith 8 ml CH₂Cl₂, and the mixture was stirred at RT over night,concentrated in vacuo and the oil was redissolved in EtOAc/1 M HCl. Theinorganic phase was extracted with CH₂Cl₂ and the organic phases werewashed with 1M HCl and brine, dried over Na₂SO₄. The crude product waspurified by flash column chromatography with EtOAc/hexane 1:1 as eluentyielding 118.2 mg (82%)[2S,4R]-2-{[acetyl-(2,5-difluoro-benzyl)-amino]-methyl}-4-acetylsulfanyl-pyrrolidine-1-carboxylicacid butyl ester as light yellow oil, MS: 443 (MHf).

[0686] Analogously, the following compounds were prepared from(2S,4R)-2-{[benzyloxy-carbonyl-(2,5-difluoro-benzyl)-amino]-methyl}-4-mercapto-pyrrolidine-1-carboxylicacid butyl ester with acetyl chloride or benzoyl chloride:

[0687](2S,4R)-4-acetylsulfanyl-2-{[benzyloxycarbonyl-(2,5-difluoro-benzyl)-amino]-methyl}-pyrrolidine-1-carboxylicacid butyl ester as colorless oil, MS: 535 (MH⁺).

[0688](2S,4R)-4-benzoylsulfanyl-2-{[benzyloxycarbonyl-(2,5-difluoro-benzyl)-amino]-methyl}-pyrrolidine-1-carboxylicacid butyl ester as colorless oil, MS: 597 (MH⁺).

[0689] 50 mg (0.09 mmol)(2S,4R)-4-acetylsulfanyl-2-{[benzyloxycarbonyl-(2,5-difluoro-benzyl)-amino]-methyl}-pyrrolidine-1-carboxylicacid butyl ester were dissolved in 130 μl 33%HBr in acetic acid andstirred at 0° C. for 30 min, and at RT for 1 h. The solution was dilutedwith ether and poured on saturated NaHCO₃ solution, carefully. Theinorganic layer was extracted with EtOAc, the combined organic phaseswere washed with water and brine, dried over Na₂SO₄ and evaporated.Column chromatography yielded 13 mg (35%)(2S,4R)-4-acetylsulfanyl-2-[(2,5-difluoro-benzylamino)-methyl]-pyrrolidine-1-carboxylicacid butyl ester as colorless oil, MS: 401 (MH⁺).

[0690] Analogously, the following compound was prepared from(2S,4R)-4-benzoylsulfanyl-2-[[benzyloxycarbonyl-(2,5-difluoro-benzyl)-amino]-methyl]-pyrrolidine-1-carboxylicacid butyl ester and isolated as hydrobromide:

[0691](2S,4R)-4-benzoylsulfanyl-2-[(2,5-difluoro-benzylamino)-methyl]-pyrrolidine-1-carboxylicacid butyl ester hydrobromide as light brown solid, MS: 463 (MH⁺).

Example 22a S-Cys-Compounds

[0692](3R,5S)-1-Methanesulfonyl-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-3-thiol(100 mg, 0.28 mmol) and Boc-Cys(Npys)-OH (105 mg, 0.28 mmol) weredissolved in argon-degassed DMF (abs. 3 ml) and degassed 0.1 M phosphatebuffer (pH 6.2, 2 ml) was added. The reaction mixture was magneticallystirred for 2 h under argon. Ethyl acetate (30 ml), water (20 ml) wereadded and the organic phase was washed with water (3×20 ml) andconcentrated under reduced pressure to give a yellow oil. The oil wasdissolved in 4 M HCl/1,4-dioxane (5 ml) for 0.5 h. Diethyl ether (30 ml)was added and the precipitated product was filtered, washed with diethylether and dried. Prep. RP-HPLC purification followed by pooling andfreeze-drying of desired fractions yielded(R)-2-amino-3-[(3R,5S)-1-methanesulfonyl-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidin-3-yldisulfanyl]-propionicacid TFA salt (148 mg), MS: 473 (MH⁻).1

[0693] Analogously, the following compound was prepared from(3R,5S)-5-Benzyloxy-methyl-1-methanesulfonyl-pyrrolidine-3-thiol:(R)-2-amino-3-[(3R,5S)-5-benzyloxy-methyl-1-methanesulfonyl-pyrrolidin-3-yldisulfanyl]-propionicacid TFA salt, MS: 419 (MH⁻).

Example 22b N-Acetyl-S-Cys-Compounds

[0694](3R,5S)-1-Methanesulfonyl-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-3-thiol(100 mg, 0.28 mmol) and Ac-Cys(Npys)-OH (89 mg, 0.28 mmol) weredissolved in argon-degassed DMF (abs. 2 ml) and degassed 0.1 M phosphatebuffer (pH 6.2, 2 ml) was added. The reaction mixture was magneticallystirred for 2 h under argon. Work-up as above (Example 22a) yielded(R)-2-acetylamino-3-[(3R,5S)-1-methanesulfonyl-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidin-3-yldisulfanyl]-propionicacid (135 mg), MS: 515 (MH⁻).

[0695] Analogously, the following compound was prepared from(3R,5S)-5-Benzyloxymethyl-1-methanesulfonyl-pyrrolidine-3-thiol:(R)-2-acetylamino-[(3R,5S)-benzyloxymethyl-1-methanesulfonyl-pyrrolidin-3-yldisulfanyl]-propionicacid, MS: 463 (MH⁺).

Example A

[0696] Tablets containing the following ingredients can be manufacturedin a conventional manner: Ingredients Per tablet Compound of formula I10.0-100.0 mg Lactose 125.0 mg Maize starch 75.0 mg Talc 4.0 mgMagnesium stearate 1.0 mg

Example B

[0697] Capsules containing the following ingredients can be manufacturedin a conventional manner: Ingredients Per capsule Compound of formula I 25.0 mg Lactose 150.0 mg Maize starch  20.0 mg Talc  5.0 mg

Example C

[0698] Injection solutions can have the following composition: Compoundof formula I 3.0 mg Gelatine 150.0 mg Phenol 4.7 mg Water for injectionsolutions ad 1.0 ml

Example D

[0699] 500 mg of compound of formula I are suspended in 3.5 ml ofMyglyol 812 and 0.08 g of benzyl alcohol. This suspension is filled intoa container having a dosage valve. 5.0 g of Freon 12 under pressure arefilled into the container through the valve. The Freon is dissolved inthe Myglyol-benzyl alcohol mixture by shaking. This spray containercontains about 100 single dosages which can be applied individually.

What is claimed is:
 1. A compound selected from the group consisting ofcompounds of formula:

wherein R¹ is hydrogen, alkylcarbonyl, or arylcarbonyl; R² is alkyl,alkenyl, alkinyl, cyanoalkyl, hydroxyalkyl, carboxyalkyl,alkoxycarbonyl, alkylcarbonylalkyl, alkylcycloalkyl,alkylcycloalkylalkyl, alkylsulfonyl, aryl, arylalkyl, arylalkoxyalkyl,aryl(alkoxycarbonyl)alkyl, arylcarbamoyl, diarylalkyl,aryl(carboxyalkyl)amide, arylamino, arylcarbonyl, arylsulfonyl,cycloalkyl, cycloalkylcarbonyl, cycloalkylalkyl, heteroaryl,heteroarylalkyl, heterocyclylalkyl, or the group YR² is heterocyclyl orR² is a group of the formula:

R³ is alkyl, alkylcycloalkyl, alkylcycloalkylalkyl, cycloalkyl,halogenalkyl, carboxyalkyl, aminoalkyl, dialkylaminoalkyl, alkoxyalkyl,alkoxycarbonylalkyl, alkinyl, aryl, arylalkyl,arylalkyl(alkoxycarbonyl)alkyl, arylcarbonylalkyl, aryloxyalkyl,arylalkenyl, aryl(alkoxycarbonyl)alkyl, heteroaryl, heteroarylalkyl,heterocyclyl or hetercycylalkyl, and R³ is hydroxy in case of X is SO₂;R⁴ is hydrogen in case m=1 or alkyl or hydrogen in case m=0; R⁵ ishydrogen, alkyl, aryl, or carboxyalkyl; R⁶ is hydrogen, alkyl, aryl,carboxyalkyl, arylcarbonyl, alkylcarbonyl, arylalkoxycarbonyl, orarylalkyl; R⁷ is hydrogen, aryl, alkyl, arylalkyl, heterocyclylalkyl,arylamino, alkyl(arylalkyl)amino, alkoxycarbonylalkyl, carboxyalkyl, oralkylthioalkyl; R⁸ is hydroxy, alkyl, aryl, cyanoalkyl, alkoxy,arylalkyl, arylalkoxy, mono- or dialkylamino, arylamino,aryl(alkyl)amino, cyanoalkylamino, arylalkyl(alkyl)amino, heteroaryl,heteroarylalkyl, or heterocyclyl; X is —S(O)₂—, —S(O)₂—NH—, —C(O)—,—C(O)NR⁵—, or C(O)O—; Y is —CH₂, —O—, —NR⁶— or —S—; and pharmaceuticallyacceptable esters, and pharmaceutically acceptable salts thereof.
 2. Thecompound according to claim 1, wherein R¹ is hydrogen or alkylcarbonyl.3. The compound according to claim 2, wherein said alkylcarbonyl isacetyl.
 4. The compound according to claim 2, wherein R¹ is hydrogen. 5.The compound according to claim 1, wherein R² is aryl, arylalkyl,arylalkoxyalkyl, arylcarbamoyl, arylamino, arylcarbonyl, arylsulfonyl,cycloalkyl, cycloalkylcarbonyl, cycloalkylalkyl, or heteroarylalkyl. 6.The compound according to claim 5, wherein R² is aryl, arylalkyl,arylcarbamoyl, arylamino, arylcarbonyl, arylsulfonyl, orheteroarylalkyl.
 7. The compound according to claim 6, wherein R² isarylalkyl.
 8. The compound according to claim 7, wherein the arylalkylof R² is phenylalkyl or phenylalkyl substituted with 2 or 3 halogenatoms.
 9. The compound according to claim 1, wherein R³ is alkyl,halogenalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, cycloalkyl,halogenalkyl, alkoxyalkyl, alkoxycarbonylalkyl, alkinyl, aryl,arylalkyl, arlyalkyl(alkoxycarbonyl)alkyl, arylcarbonylalkyl,aryloxyalkyl, arylalkenyl, aryl(alkoxycarbonyl)alkyl, heteroaryl,heteroarylalkyl, or heterocyclyl.
 10. The compound according to claim 9,wherein R³ is alkyl, arylalkyl, arylcarbonylalkyl, aryloxylakyl,alkylcycloalkyl, alkylcycloylkylalkyl, cycloalkyl, heteroarylalkyl, orhalogenalkyl.
 11. The compound according to claim 10, wherein R³ isalkyl, arylalkyl, aryl, aryloxyalkyl, or halogenalkyl.
 12. The compoundaccording to claim 1, wherein R⁴ is hydrogen.
 13. The compound accordingto claim 1, wherein X is —S(O)₂—, —S(O)₂—NH—, —C(O)NR⁵—, or C(O)O—. 14.The compound according to claim 13, wherein X is —S(O)₂—, —C(O)NH—, orC(O)O—.
 15. The compound according to claim 1, wherein R⁵ is hydrogen,alkyl, or carboxyalkyl.
 16. The compound according to claim 15, whereinR⁵ is hydrogen.
 17. The compound according to claim 1, wherein R⁶ ishydrogen, alky. or arylalkyl.
 18. The compound according to claim 17,wherein R⁶ is hydrogen.
 19. The compound according to claim 1, whereinR⁷ is hydrogen or aryl.
 20. The compound according to claim 1, whereinR⁸ is hydroxy or alkoxy.
 21. The compound according to claim 1, whereinY is —O—.
 22. The compound according to claim 1, wherein Y is —NH—. 23.The compound according to claim 1, wherein R¹ is hydrogen oralkylcarbonyl; R² is arylalkyl that is phenylalkyl substituted with 2 or3 halogen atoms; R³ is alkyl, aryl, arylalkyl, aryloxyalkyl, orhalogenalkyl; X is —SO₂—, —CONH—, or —C(O)—O—; and Y is —NH— or —O—. 24.The compound according to claim 23, wherein said alkylcarbonyl of R¹ isacetyl, and R² is difluorobenzyl, or trifluorobenzyl.
 25. The compoundaccording to claim 1 which is(3R,5S)-5-[(2,5-difluoro-benzylamino)-methyl]-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiol.26. The compound according to claim 1 which is(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid (2-fluoro-phenyl)-amide.
 27. The compound according to claim 1which is(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid 4-methoxy-phenyl ester.
 28. The compound according to claim 1 whichis(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid 4-fluoro-phenyl ester.
 29. The compound according to claim 1 whichis(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid isopropyl ester.
 30. The compound according to claim 1 which is(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid naphthalen-2-yl ester.
 31. The compound according to claim 1 whichis(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo[1,4]dioxin-5-yl ester.
 32. The compound accordingto claim 1 which is(2S,4R)-2-[(2,5-difluoro-benzylamino)-methyl]-4-mercapto-pyrrolidine-1-carboxylicacid butyl ester.
 33. The compound according to claim 1 which is(3R,5S)-1-(butane-1-sulfonyl)-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-3-thiol.34. The compound according to claim 1 which is(3R,5S)-1-methanesulfonyl-5-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-3-thiol.35. The compound according to claim 1 which is(2S,4R)-4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid benzylamide.
 36. The compound according to claim 1 which is4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid butylamide.
 37. The compound according to claim 1 which is4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid (2-phenoxy-ethyl)-amide.
 38. The compound according to claim 1which is4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid (2,2,2-trifluoro-ethyl)-amide.
 39. The compound according to claim1 which is4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonicacid 4-fluoro-benzylamide.
 40. The compound according to claim 1 whichis4-{[4-mercapto-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-sulfonylamino]-methyl}-benzoicacid.
 41. The compound according to claim 1 which is(2S,4R)-4-acetylsulfanyl-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo[1,4]dioxin-5-yl ester.
 42. The compound accordingto claim 1 which is(2S,4R)-4-acetylsulfanyl-2-[(2,5-difluoro-benzylamino)-methyl]-pyrrolidine-1-carboxylicacid butyl ester.
 43. The compound according to claim 1 which is(2S,4R)-4-acetylsulfanyl-2-(2,4,5-trifluoro-benzyloxymethyl)-pyrrolidine-1-carboxylicacid 2-methoxycarbonyl-phenyl ester.
 44. The compound according to claim1 which is(2S,4R)-1-[1-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-5-methyl-1H-[1,2,3]triazol-4-yl]-ethanone.45. The compound according to claim 1 which is(2S,4R)-1-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-5-methyl-1H-[1,2,3]triazole-4-carboxylicacid ethyl ester.
 46. The compound according to claim 1 which is(3R,5S)-5-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiol.47. The compound according to claim 1 which is(2S,4R)-5-amino-1-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-1H-[1,2,3]triazole-4-carboxylicacid amide.
 48. The compound according to claim 1 which is(3R,5S)-5-(5-amino-4-phenyl-[1,2,3]triazol-1-ylmethyl)-1-(naphthalene-2-sulfonyl)-pyrrolidine-3-thiol.49. The compound according to claim 1 which is(2S,4R)-1-[4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethyl]-5-methyl-1H-[1,2,3]triazole-4-carboxylicacid ethyl ester.
 50. The compound according to claim 1 which is(3R,5S)-1-methanesulfonyl-5-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-3-thiol.51. The compound according to claim 1 which is(2S,4R)-1-[4-mercapto-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-ylmethyl]-5-methyl-1H-[1,2,3]triazole-4-carboxylicacid.
 52. The compound according to claim 1 which is(2S,4R)-5-amino-1-[4-mercapto-1-methanesulfonyl-pyrrolidin-2-ylmethyl)-1H-[1,2,3]triazole-4-carboxylicacid amide.
 53. The compound according to claim 1 which is(3R,5S)-5-(5-amino-4-phenyl-[1,2,3]triazol-1-ylmethyl)-1-methanesulfonyl-pyrrolidine-3-thiol.54. The compound according to claim 1 which is(2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid benzyl ester.
 55. The compound according to claim 1 which is(2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid isopropyl ester.
 56. The compound according to claim 1 which is(2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid phenyl ester.
 57. The compound according to claim 1 which is(2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid naphthanlen-2-yl ester.
 58. The compound according to claim 1 whichis(2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid 2,3-dihydro-benzo[1,4]dioxin-5-yl ester.
 59. The compound accordingto claim 1 which is(2S,4R)-4-mercapto-2-(5-methyl-4-phenyl-[1,2,3]triazol-1-ylmethyl)-pyrrolidine-1-carboxylicacid butyl ester.
 60. A pharmaceutical composition comprising a compoundaccording to claim 1 and a pharmaceutically acceptable excipient.
 61. Adimeric form of a compound of the formula:

wherein R¹ is hydrogen, alkylcarbonyl, or arylcarbonyl; R² is alkyl,alkenyl, alkinyl, cyanoalkyl, hydroxyalkyl, carboxyalkyl,alkoxycarbonyl, alkylcarbonylalkyl, alkylcycloalkyl,alkylcycloalkylalkyl, alkylsulfonyl, aryl, arylalkyl, arylalkoxyalkyl,aryl(alkoxycarbonyl)alkyl, arylcarbamoyl, diarylalkyl,aryl(carboxyalkyl)amide, arylamino, arylcarbonyl, arylsulfonyl,cycloalkyl, cycloalkylcarbonyl, cycloalkylalkyl, heteroaryl,heteroarylalkyl, heterocyclylalkyl, or the group YR² is heterocyclyl orR² is a group of the formula:

R³ is alkyl, alkylcycloalkyl, alkylcycloalkylalkyl, cycloalkyl,halogenalkyl, carboxyalkyl, aminoalkyl, dialkylaminoalkyl, alkoxyalkyl,alkoxycarbonylalkyl, alkinyl, aryl, arylalkyl,arylalkyl(alkoxycarbonyl)alkyl, arylcarbonylalkyl, aryloxyalkyl,arylalkenyl, aryl(alkoxycarbonyl)alkyl, heteroaryl, heteroarylalkyl,heterocyclyl or heterocycylalkyl, and R³ is hydroxy in case of X is SO₂;R⁴ is hydrogen in case m=1 or alkyl or hydrogen in case m=0; R⁵ ishydrogen, alkyl, aryl, or carboxyalkyl; R⁶ is hydrogen, alkyl, aryl,carboxyalkyl, arylcarbonyl, alkylcarbonyl, arylalkoxycarbonyl, orarylalkyl; R⁷ is hydrogen, aryl, alkyl, arylalkyl, heterocyclylalkyl,arylamino, alkyl(arylalkyl)amino, alkoxycarbonylalkyl, carboxyalkyl, oralkylthioalkyl; R⁸ is hydroxy, alkyl, aryl, cyanoalkyl, alkoxy,arylalkyl, arylalkoxy, mono- or dialkylamino, arylamino,aryl(alkyl)amino, cyanoalkylamino, arylalkyl(alkyl)amino, heteroaryl,heteroarylalkyl, or heterocyclyl; X is —S(O)₂—, —S(O)₂—NH—, —C(O)—,—C(O)NR⁵—, or C(O)O—; and Y is —CH₂, —O—, —NR⁶—, or —S—.